Mr Oldham says while the theft of historic items - including medals - is relatively frequent, the black market is smaller than people may think.
"I get notifications all the time of stuff that's gone missing, but none of it ever seems to turn up. It's hard to tell where it really goes," he said.
"It's opportunists. They just burgle some place, take some medals and don't know what to do with them once they've got them.
"Sometimes they throw them away, sometimes they flog them off, but really they hardly ever turn up."
Following the burglary, Auckland RSA urged for them to be returned to their rightful owner.
"We ask that all medal and military collectors and public watch out for these medals (they are engraved) should they come on to the market."