Stephen Turvey has been missing from his Glenfield home for more than 40 years and Macarthur police desperately want anyone with information about his disappearance to come forward.
The then-15-year-old was last seen at home about 1pm on Saturday, November 13 in 1976.
Mr Turvey went for a bike ride and was expected home later that afternoon. His family reported him missing to the police when he did not arrive home.
Mr Turvey is one of at least six people missing from the Macarthur region.
The NSW Police Force recently announced the Missing Persons Unit would be dissolved and a new unit would be established to investigate and coordinate long-term missing persons cases.
NSW Police Commissioner Michael Fuller said the new structure would draw on the expertise of specialist detectives and analysts.
"It is clear that change is needed and I have delegated responsibility to the State Crime Command to ensure we can do everything we can to put policies, procedures and checkpoints in place to rectify past problems and create solutions for now and into the future," he said.
"To have a loved one go missing has a devastating impact on the person's family and friends and while police do an outstanding job in providing support for the families, we are committed to providing outcomes.
"It needs to be acknowledged that families of missing persons have not been given the answers they have been seeking, and this is not acceptable.
"We owe it to the people of NSW to deliver better outcomes for families of missing persons and vulnerable people who are most at risk of going missing - those living with a mental illness, young people, and older people with dementia or memory loss - to ensure every opportunity is explored to find loved ones, wherever they may be."
The new Missing Persons Registry will be formed in a new state-of-the-art facility with a team of seven detectives and four analysts.
Using the registry's new systems more than 30 cases have been resolved, with 13 people located offshore or interstate in recent months.
Stephen Turvey is just one of the long-term missing people cases currently open in Macarthur.
The region's other missing people include then-16-year-old Debbie Ashby who was last seen leaving her Leumeah home on October 9, 1987, and Stephen Roach who was last seen in Ingleburn on November 9, 1993.
There was a renewed push for information in the disappearance and suspected murder of Macarthur's Tracey Valesini in 2017.
Ms Valesini was last seen at Campbelltown Courthouse on January 8, 1993. She had been attending a custody hearing for her daughter, Crystal-Lee, then two.
The matter was to return to court on February 12, but Ms Valesini failed to appear. Her family never heard from her again.
On what would have been Ms Valesini's 45th birthday, her family launched a public appeal for information, accompanied by detectives from the NSW Unsolved Homicide Team.
The state government announced a $100,000 reward for information in 2017.
Ian Hollis left his family home in Minto on May 15, 1986 and has not been seen since, and Camden's Mark Goldsmith was last seen in Sydney's inner-west on January 5, 2010.