"It's getting more serious in terms of the type of images we're seeing. You're getting made to order type stuff now," she said.
"It gets worse and worse."
Recent UN research found there were one million clicks a day on objectionable material around the world and the upward trend has seen Customs push more resources into the area.
Customs manager of investigations Maurice O'Brien said the two dedicated officers who worked on child exploitation would likely become 3.5 this year, joining the wider team of the Customs Investigation Unit.
"As we dig deeper and deeper, the level of seriousness and depravity, even for us it's eye opening," he said.
"I'm a father and it's beyond comprehension. When we see objectionable material, we're not talking about Hugh Hefner and the Playboy mansion. We're talking about real people being hurt and victimised. Real people."
Operation Hyper saw four New Zealanders from truckies to high-flying executives brought to justice - two were jailed and two received sentences of home detention.
Ms Singh said the way the men described the victims was as horrific as she had seen.
The men referred to the girls as "whores" and "sluts" and the fact they chatted to each other online allowed them to feed off each other's perversion, she said.
By the time search warrants were executed, the men had filmed themselves enjoying the child-abuse videos and when one man was asked whether he had offended against his 6-year-old daughter he said "not yet".
Police did not find evidence of any of the defendants abusing children in their care but a 6-year-old girl was removed from the home of a UK-based ring member who was also arrested.
Since taking over the role Ms Singh had made it standard policy to put the offensive images before the judge so they could see exactly what they were dealing with.
In collaboration with police department Online Child Exploitation Across New Zealand (OCEANZ), Customs also developed a database of known victims of child-abuse imagery.
"It is to highlight these are real victims. It's not a victimless crime," Ms Singh said.
Mr O'Brien paid tribute to his staff who he described as "very committed" but he was keen to warn people the problem was not going away.
"I don't want to scare people but to me awareness of the seriousness and the depravity of some of the imagery that's circulating around the world is very important."
Timeline
June 2013
- Investigations by Queensland police uncovers information relating to a NZ offender and contacts Customs.
US Homeland Security Investigations also refer a suspect to DIA.
Customs executes a search warrant with police assistance. Electronic exhibits are located and uplifted and a child at the address is assessed.
July 2013
- Customs finds evidence of a network of NZ offenders trading imagery and chatting about abusing children.
Further intelligence identifies three NZ offenders.
A UK-based offender is identified and referred to UK police
September 2013
- Three simultaneous search warrants are executed in Levin, the North Shore and the UK.
West Yorkshire Police and arrest and charge a man. His 9-year-old granddaughter is protected.
Another UK offender is identified by OCEANZ through forensic examination of electronic equipment belonging to Levin man Gary Barnes.
December 2013
- West Midlands police in the UK arrest and charge a man. His 6-year-old granddaughter - a victim of the offending - is removed.
Customs execute a warrant for the fourth NZ offender, in Northland. Two children living at the property are assessed.
Sentenced
Feb 2015
- 51-year-old North Shore man Michael Beer - 1 year home detention, 400 hours of community work
Aug 2014
- 33-year-old Northland man David Roycroft - 1 year 11 months jail
June 2014
- 42-year-old Auckland man with name suppression - 10 months home detention
June 2013
- 54-year-old Levin man Gary Ronald Barnes - 2 years 5 months jail
*Police were unable to give details about the UK offenders
