Police say they're pleased with the response to the offer of a $50,000 reward and immunity from prosecution for information on the cold case homicide of a teenage sex worker.
Jane Furlong was last seen on Auckland's Karangahape Road in May 1993. The remains of the 17-year-old were found at a Port Waikato beach in May last year.
Police say new people have come forward since the reward was offered on 21 March.
However people who had previously refused to be interviewed haven't changed their stance.
Detective Inspector Mark Benefield said among those keeping silent is Ms Furlong's boyfriend at the time, Danny Norsworthy, who he believes holds key information about the case.
Ms Furlong's mother Judith Furlong said the reward and the immunity should have been offered earlier.
She said 20 years is a long xtime and she is losing hope that anyone will be held accountable for what happened to her daughter.