A peculiar tattoo and a new computerised image could help detectives crack a four-decades-old cold case.
An unidentified man - believed to be using an alias - was struck and killed by a train in Sydney's inner west more than 40 years ago.
He died on the tracks between Stanmore and Newtown stations on the afternoon of April 14, 1981.
Police have released a computerised image and a photo of the man's distinctive tattoos.
Following a 2021 review of cold cases, a fingerprint analyst identified the man as possibly being Osvaldo Perez born on May 16, 1955, and residing in a boarding house in Fairfield East.
At the time he was believed to be employed as either a labourer or boiler maker.
But detailed investigations both in Australia and abroad have failed to establish any such person existed.
While there are no suspicious circumstances, police have never been able to identify the man, though he was arrested by Cabramatta police on New Year's Day in 1981 for drink driving.
Detective Inspector Ben Kennis said the two arresting officers from the time as well as the original investigator into the man's death have been contacted for assistance.
"To say these former officers were shocked when we contacted them would be an understatement," he said.
"Surprisingly, one of the officers who had dealings with the man actually remembered him and was able to supply beneficial information to detectives."
Retired Inspector George Georgiou said he had always been troubled by the cold case.
"Back in those days we did not have the technology that police now have available to them," he said.
Tattoo artists of the time are also helping detectives.
On his left thigh, the man had a woman wearing a bikini and holding a bunch of flowers, an eye and the words Eulrlia and Stevios.
The origin of these words could possibly be either Greek or Spanish.
He also had a rose on his left shoulder blade.
The man was described as being of South American appearance, 176cm tall, aged between 25 and 30 years of age, of medium build, olive complexion, with black curly collar-length hair, a black moustache and spoke with an accent.
At the time he was wearing a yellow and brown patterned shirt, blue denim straight leg jeans and brown boots.
Located in the man's possession was a $20 note, an Aseikon brand gold coloured watch and a weekly train ticket allowing travel between Stanmore and Canley Vale.
It is believed the man may have had links to Fairfield's Romanian community.