Key Points:

A ring of brazen thieves is taking jewellery boxes in a spate of daylight burglaries across Auckland's poshest suburbs.

Priceless heirlooms have been stolen from eastern suburb homes by opportunistic burglars, possibly working in pairs, who are targeting families new to the area.

A private investigator tracking the missing treasures says a pattern is emerging, as a number of people have called him with similar stories.

Owners fear the jewellery is being pawned by unscrupulous brokers outside Auckland or overseas, or worse, that more distinctive pieces are being melted down.

Two weeks after Glenis and Chris Parker moved into Epsom they discovered that more than $50,000 of treasured trinkets had been taken from their new home.

The thief, who walked in while the Parkers were home, sneaked upstairs and dropped the heavy oak box out the window into the garden.

An accomplice was either waiting below, or returned later that night to retrieve the stolen goods.

Only half the jewellery was insured but Glenis said the heirlooms were priceless and irreplaceable.

Antique pieces handed from generation to generation are gone, as well as a silver bracelet with 25 charms - one for each wedding anniversary.

Sadly, a number of "silly little things" which were going to be given to her daughter for her wedding day in February were also taken: a garter, a great-grandmother's hankie which Glenis carried at her own wedding, and five silver buttons from a great, great grandmother's wedding dress.

"Today's the first day I haven't cried," she said on Friday. "I get wild when I think about it.

"I wouldn't have cared if someone had taken all the whiteware. But this is just devastating. You can't replace all that beautiful family stuff but it means nothing to a burglar. They'll probably flog them at a flea market."

Although they were home during the burglary, the Parkers have upgraded their security system and changed the locks. Christmas holidays were cancelled and they've received calls from a caller who hangs up immediately. They hired private investigator Mike Campbell to track down the thieves. A number of other families in Epsom, Remuera and Newmarket have come forward with similar stories.

"It's a very opportunist crime in one of Auckland's top streets," Campbell said. "Patterns emerge on these things, I've had a lot of calls of similar offending and we've even got a suspect car and a vague description."

Senior Sergeant Hirone Waretini of Mt Wellington police said: "It's a huge problem for the victims. In terms of current crime patterns that we can develop tactics for, we're waiting to see what happens, especially when people get back from holiday break."

Burglars had different motivations, said Waretini. Some steal property that is easy to sell at second hand dealers and on auction websites to get money for drugs - or as part of an organised crime group.

Offenders also sell goods directly to receivers of stolen property.

Rather than investigate every burglary that has no obvious lines of enquiry, police try to link groups of burglaries in a pattern and build up an extensive profile. When a suspect is identified police can then interview that person on a significant number of offences.

"Certainly we never give up hope of catching the crooks," Waretini said.

A reward has been offered for information leading to the recovery of the jewellery. 0800 384 427 can be called in confidence.