One of New Zealand's biggest unsolved murder mysteries is being resumed after nearly 40 years.
Waitemata Police this morning revealed they are working on fresh leads in the murder of Tracey Ann Patient, who was strangled and her body found dumped in the Waitakere Ranges on January 30, 1976.
A team of detectives have been working fulltime on the cold case since November last year and following fresh lines of inquiry, including interviewing people in Australia in a bid to find the killer of the Auckland teenager.
Tomorrow marks 40 years to the day since the 13-year-old disappeared while walking home from a friend's house.
On the night of January 29, 1976, Tracey went to a friend's house in Chilcott Road, Henderson. She was due to be back home at her parent's house in Dellwood Avenue at 9.30pm.
Tracey's friend walked her halfway home and they parted at the intersection of Great North Rd and Edmonton Rd at around 9.30pm.
She set off up Great North Rd. The last known sighting of Tracey was outside No 295 Great North Rd in Henderson. She was only five minutes walk from her home.
The following morning, a man walking his dog found her body in a bush area on Scenic Drive. She had been strangled with a stocking and her body discarded just metres into the bush area.
A large-scale investigation was launched and over the following months police looked at hundreds of persons of interest and exhausted numerous lines of enquiry.
Twenty-two months after Tracey's murder (November 1978), police received a phone call from an anonymous person, who told them that a signet ring Tracey owned was in a rubbish bin outside a chemist in Avondale.
The caller gave the calltaker the number "126040" and said he would call back later.
Officers went to the rubbish bin and found a ring inside, which is believed to have been the ring Tracey was wearing when she went missing and had been given to her by a boyfriend.
Despite more than 850 persons of interest being profiled over the 40 years since Tracey's murder, no one has been identified and charged.
Police have continued to receive hundreds of pieces of information about the case, including theories around the "126040" number and nominations for persons of interest. Despite thousands of hours of investigative work, Tracey's killer remains unidentified.
Detectives are now following new leads and are now appealing for anyone with information on the case to call 0800 000 111.
Detective Sergeant Murray Free has been on the case for the past 12 years, he is leading the investigation team, with oversight from Detective Inspector John Sutton.
In the past three months, detectives have made inquiries with a number of people, as far away as Australia.
"Despite 40 years having passed, someone out there knows who did this," Det Sgt Sutton said.
"To this day we still have people who ring us with information, and I'm pleased to say we are following new leads.
"For 40 years, the Patient family have lived with the absolute trauma of what happened to their daughter and sister, they have never known who took Tracey from them or why.
"It is still incredibly fresh to them, as if she was stolen from them only yesterday.
"The West Auckland community remember this well. It was horrific; a 13-year-old girl with her whole life ahead of her, just minutes away from home and brutally murdered. Someone out there knows who did this, and we are as determined to solve it now as we were back then.
"Speaking on camera for the first time ever, Tracey's older sister Debbie has filmed an interview with police to help with our public appeal."
"The eight-minute video, which is available on the Waitemata Police Facebook page, will give those who are not familiar with this case some idea of Tracey's story and the catastrophic effect this crime had on an entire family."