Police have offered more than $1.65 million in reward money since 1999 in a bid to solve some of the country's most enduring cold-case crimes.
But barely any cases have been solved as a result, and only a handful of people have made any money by coming forward.
In the last 20 years there have been 34 cases - mostly murders - where police have offered a cash reward as an incentive for people to come forward with information that would lead to an arrest or prosecution.
In three cases a reward was later reissued with a higher value to further prompt people connected to crimes to reach out to police.
Police have confirmed that in two cases rewards, or part of, were paid, but refuse to say if any further cash has been handed out in relation to the other cases.
In 2007 a whopping $300,000 was offered for information that led to the identity and conviction of the person responsible for stealing 96 medals, including nine Victoria Crosses, from the Waiouru Army Museum.
The reward was funded by British peer Lord Michael Ashcroft and Nelson businessman Tom Sturgess.
A month later Auckland lawyer Chris Comeskey approached police on behalf of the thieves and brokered a deal for the return of the medals in exchange for the cash.
The medals were returned in February 2008 and James Kapa and Ronald van Wakeren were each paid $100,000.
The pair were later arrested with only van Wakeren returning his share of the reward spoils.
In 2007 Nai Yin Xue murdered his wife An An Liu and - after dumping her body in the boot of the family car - and fled New Zealand with their 3-year-old daughter.
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He abandoned the toddler at a Melbourne railway station and flew to the United States.
A reward of US$10,000 was offered for information leading directly to the arrest of the killer.
He was eventually caught on the outskirts of Atlanta, Georgia, after a nationwide US manhunt.
The reward was paid in full.
The majority of rewards only remain on offer for a matter of months.
At the moment there are two major rewards of $100,000 on offer - relating to the murders of Katrina Jefferies in Auckland in 2005, and Angela Blackmoore in Christchurch in 1995.
Detective Senior Sergeant Scott McGill said other than those "publicly announced" rewards, police would not reveal what, if any, other cash had been handed over.
"Police are not prepared to disclose details of any other payments as police consider it would be likely to prevent members of the public coming forward in the future," he said.
"The making available of the information is likely to prejudice the maintenance of the law including the prevention, investigation and detection of offences and the right to a fair trial."
McGill said the information was also being withheld in order to protect information which was "subject to an obligation of confidence".
"The making available of the information would be likely to prejudice the supply of similar information, or information from the same source, and it is in the public interest that such information should continue to be supplied," he said.
McGill said rewards were posted to encourage the public to supply material information leading to the conviction of people responsible for committing a serious crime or to help police find a or long-term missing person suspected of being the victim of crime.
They could also be offered for or the return of lost or stolen property, or to clarify and or resolve police investigations.
The police Posting of Rewards Guidelines state the incentives are offered "after all practical leads have been exhausted and an investigation stalls" - but they may be offered at any stage within an operation and "should be part of an overall investigation plan".
Funding for a reward comes directly from the police district involved, either from organisational budgets, in conjunction with an external agency or from individual funding.
Rewards are posted "in the interest of public satisfaction and safety, victim focus and offender apprehension".
"Police have a responsibility to explore all options and avenues in reducing and resolving crime," the guidelines state.
Even if a reward is posted, police must still "remain diligent and victim-focused in achieving incident resolution".
"If deemed appropriate under the circumstances, staff will consider and/or request to post a reward for material information, all procedures will be adhered to and transparent in obtaining approval to fund and post a reward, all staff remain diligent and victim-focused in achieving incident resolution.
Families of those missing or murdered where rewards were offered have urged people with crucial information to come forward.
"We want justice for Katrina and it pains me that her killer is still out there somewhere," said Jefferies' mother Nicola.
"Our family want to move on and I still hold out hope that police will find who did this to Katrina.
"I urge anyone who saw Katrina and knows what happened to contact police."
Blackmoore's partner Laurie Anderson told the Herald recently that he was now confident her case would be solved after the reward was offered.
"The scum factor, who knows who's done it, only care for themselves,' he said.
"So now there's an interest for someone to make a gain, [the killer] will be very scared."
POLICE REWARDS - 20 YEARS, $1.65 MILLON OFFERED
$50,000 offered in the months after the shocking murder of Ashburton teenager Kirsty Bentley. The 15-year-old disappeared on December 31, 1998, while walking the family dog, Abby, on the Ashburton riverbank. The dog was found tied to a tree near the river the next day, and Kirsty's underwear was nearby. Her body was discovered two weeks later in the Rakaia gorge, 40km away. The reward was withdrawn a year later after failing to bring any new information. To date, no one has been charged in relation to Bentley's death.
$50,000 after the murder of Terri Robert King aka Trevor Raymond Heath who was shot near Powell Hut in the Tararua Ranges on or about 13 April 1999.
$10,000 for information on the burglary of the Cherrywood Branch of Westpac Trust Bank in Tauranga where $119,000 was stolen from the ATM using a sixteen digit PIN number to gain access.
$50,000 for the murder of Justin Robert Dyne, last seen alive within the Tui Glen Motor Camp, Henderson on July 25 2000. His decomposed body was found in the Waitakere Ranges on September 12 2000.
SOLVED: Tristan Rex Lawson, 23, convicted of murder, jailed for life.
$50,000 around the death of Jason Raymond Kearney, believed to have been murdered. Kearney left his Papakura home on August 17 1996 in his car, which was later found parked near a dam in the Hunua ranges.
$10,000 for the robbery of Ye Corner Dairy in Whangarei on June 8, during which a shot was fired, wounding the shop owner.
$50,000 for the murder of Marie Jamieson, whose naked decomposing body was located behind a factory in Mihini Rd, Henderson on February 19, 2001.
SOLVED: Joseph Martin Reekers convicted of murder in 2010, jailed for life with a minimum non-parole period of 15 years.
$50,000 for the disappearance of Phillip John Cowan suspected of being murdered at Wellington on or about March 31,2001. Cowan was a drug dealer and the disappearance is thought to have resulted from his illegal activities.
$15,000 offered for the arson of a dwelling house situated at 199 Trices Rd, Prebbleton.
$20,000 for the murder of George Matahaere on December 16, 2002. Matahaere, who identified as a woman, was hit five times in the face with her own baseball bat in her room at a South Auckland housing project.
$20,000 for the disappearance and death of Sara Louise Neithe. The Kerepehi mother-of-three vanished on March 30, after an evening of drinking in nearby Kaihere with friend Mark Pakenham. In September 2003 the reward was increased to $50,000. After nobody had come forward to collect the earlier reward, it was increased to $50,0000
SOLVED: In 2013 Pakenham was jailed for Neithe's manslaughter but to date, he refuses to disclose where her body is.
$5,000 for Operation Illusion for material information or evidence which led to the apprehension of two suspects wanted for failing to meet their bail conditions.
$20,000 for Operation Gerona. The reward was offered for information leading to two offenders for the attempted murder and sexual violation of a 14-year-old South Auckland girl. One offender had already been charged when this reward was issued.
$50,000 for the disappearance of Margaret Kaye Stewart who went missing while out on a walk in the Rimutaka Forest Park at Wainuiomata on June 13, 2005.
$50,000 for the disappearance of Nicholas Pike who was last seen alive in March 2002 with friends in Mt Maunganui.
SOLVED: Stephen Thomas Hudson was found guilty of murdering Pike, but his body has never been found.
$50,000 for the death of Katrina Jefferies whose body was found on in the Waikowhai Reserve in Hillsborough in July 2005. Earlier this year the reward was reissued. Police are now offering $100,000 reward and immunity from prosecution to anyone who can help solve the cold case murder of the young Auckland mother.
$50,000 offered over the disappearance of Grant Trevor Adams who was last seen alive in Tauranga in November 2005. Known as Granite, the 29-year-old was last seen by flatmates and was reported missing by his mother after failing to show up for Christmas and his daughter's birthday. Police said Mr Adams was a drug user involved in manufacturing methamphetamine and is believed to have been killed after a "rip-off" of others involved in making the drug. In July 2007 Adams' body was found, buried at the Wairakei geothermal power station near Taupo early. Brett Michael Ashby was charged with Adams' murder. Ashby pleaded not guilty and died of cancer while awaiting trial.
$50,000 for the disappearance of Joanne Chatfield, who was last seen alive in November 1988, leaving a function at the University of Auckland campus and walking down Princes St towards Wellesley St. The reward was reissued in December 2018 but to date no one has been charged and Chatfield has not been found.
US$10,000 offered for information on Nai Yin Xue murdered his wife An An Liu and dumped her in the boot of the family car before fleeing NZ. He also abandoned their 3-year-old daughter at a Melbourne railway station on his way to the US, where he was eventually caught.
SOLVED: Xue was jailed for life, despite denying a charge of murder.
$300,000 offered for material information that led to the identity and conviction of person/s responsible for the burglary of the Waiouru Army museum in which 96 medals including 9 Victoria Crosses were stolen.
SOLVED: Ronnie Van Wakeren and James Kapa were convicted for the theft. Both received $100,000 in reward money. Van Wakeren returned his share and Kapa claims his was taken by someone else.
$75,000 for the grisly murder of Japanese tourist Kayo Matsuzawa.The 29-year-old was murdered in 1998, just hours after she arrived in Auckland. Her naked body was dumped in an obscure utility cupboard in a warren-like CBD building. Last year police revealed they had identified a new suspect in the 20-year-old cold case - a man who used a bank card at a BNZ ATM machine the day Matsuzawa disappeared.
$50,000 for the disappearance of Darrell James Crawford who was last seen alive in Tauranga in August 2007. His body has not been found. Te Puke man Mark Haimona Puata was charged with Crawford's murder but that was later discharged.
$50,000 for the disappearance of William Taikato who was last seen alive in Tauranga in December 2007. At a trial in the High Court at Rotorua, the Crown alleged Taikato and Crawford - both heavily involved in the drug scene - were murdered on separate occasions, and their bodies dumped in a shared grave. Mark Puata, John Aitken and David Anderson were all charged with Taikato's murder but were acquitted after a jury trial.
$50,000 for the death of Mellory Manning, also known as Ngatai. She was last seen alive in Christchurch in December 2008. It later emerged that the 27-year-old was abducted by Mongrel Mob members, raped and murdered as a result of a drug debt. Her body was found the next morning in the Avon River. Mauha Fawcett was found guilty of murder in the High Court at Christchurch and jailed for life. However his conviction was quashed on appeal. Police have ordered a new trial, and have always said they believe others were involved in Manning's death. To date no further charges have been laid.
$20,000 offered in relation to the disappearance of Tisha Cecilia Lowry who was last seen alive in Christchurch in September 2008.
SOLVED: in May 2010 Lowry's neighbour Jason Somerville was jailed for life for her murder. He came to police attention after his reporting his wife Rebecca Chamberlain. He later admitted to killing both women and burying them under his Aranui home. He also told police he had sex with both women's bodies after he took their lives.
$50,000 for the murder of Claire Hills. Hills was still alive when she was doused in petrol and set alight in her car on Mangere Mountain in Mangere Domain, south Auckland, on April 29, 1998. Police believe she was abducted on her way to work early in the morning, taken to the domain and murdered in her car. A $50,000 reward posted about four months after her death was one of the biggest ever offered in New Zealand but produced no significant leads. In 2009 the reward was reissued, but to date no one has been charged in relation to Hills' brutal death.
$50,000 for the murder of Jordan Voudouris in June 2012 at Paeroa. Voudouris' body was found at the back of his pizza shop. He had been fatally shot.
$50,000 for the murder of Jane Furlong between May 1993 and the May 2012 when her body was found on Sunset Beach, Port Waikato. The 17-year-old mother of one was last seen on Auckland's Karangahape Rd where she worked part time in the sex industry. To date, no one has been charged with her disappearance or murder.
$20,000 to help find Simon James Garrick who had vanished.
SOLVED: Garrick's body was located in October 2013 and police do not consider his death suspicious s.
$50,000 to find Luana Deborah La Verne Williams or her body. She was reported missing by her partner after he got home from a night out to find her gone. Williams was declared legally dead in 1998 but, to date, no one has been held responsible for her demise.
$50,000 to find Tuitania Barclay or her body. About a month before her disappearance, Barclay had indicated she was going to end her relationship with partner Bill Brown. He did not report her missing until four months after the last confirmed sighting, and had since relocated to Britain. He said at the time he believed his partner had gone back to her former life of drug-taking and prostitution, though she was still breastfeeding the youngest of their two children when she disappeared.
$30,000 to find Yoon Sook Chun and/or her body. Chun went missing from Christchurch in 2009, after emailing her family saying she was going to Auckland for a break.The Korean mother-of-two has not been seen since and police say she is either still alive and being helped by someone, or is dead.
$50,000 for the murder of Brett Gene Fraser. Fraser was killed in October 2014 at the warehouse property he shared with his flatmate in Westech Place, Glen Eden. Police believe the incident was motivated by a cannabis robbery - Fraser's flatmate was running a cannabis growing operation at the warehouse and had recently harvested his plants.
In December 1996 a $20,000 reward was offered in regard to the murder of Angela Maree Blackmoore who was stabbed 39 times at her home address of 48 Vancouver Cres, Christchurch. The young mother-of-one was 10 weeks pregnant and her body was discovered by her partner when he returned home from work. The initial reward remained in force until June 1997 and was not renewed. Earlier this year a new $100,000 reward was issued. It is valid until September 16 this year.
CAN YOU HELP?
If you have information about any of the unsolved cases, police would like you to contact your local police station, or call the non-emergency number 105.
Alternatively, you can pass on information anonymously via the Crimestoppers reporting line on 0800 555 111.
You can also email the Herald by clicking here: