Ms Thode said police had confirmed the rings were sold but that the jeweller had done nothing wrong.
"[The pawn shop owner] has unfortunately sold them to an unknown buyer for cash, which is why they can't be traced."
Secondhand dealers are governed by strict rules, according to the police website.
They must keep records of sellers, including their full name, address, phone number, date of birth and verification of authorised ID.
Dealers did not have to keep a record of anyone they then sold to.
Police said they had charged someone with stealing the rings and they were due to appear in court next week.
NZME. np cr pd