Police are hopeful the man in the image, which they released to the public on Thursday, can help them solve the mystery around the disappearance of Revelle Balmain more than 26 years ago.
Ms Balmain, aged 22 at the time, was last seen in Sydney's Kingsford on November 5 1994. Her mother, a Soldiers Point ballet teacher, had been due to meet her at Newcastle train station but her daughter never arrived.
She was reported missing that evening and has not been seen or heard from since, police said.
No-one has ever been charged over her disappearance. In 1999 a coroner found Ms Balmain had died at the hands of a person or persons unknown.
Her matter was referred to the Unsolved Homicide Unit, who conducted a formal review of the case in 2020. They have since commenced re-investigation, forming Strike Force Aramac and announced a $1 million reward for information in May.
Detectives say they received several reports from the community relevant to the investigation. They are assessing those tips and identifying how their inquiry should proceed.
One of those avenues is identifying the man in the image, police said, who they hope may have information regarding Ms Balmain's last movements.
Police received the image anonymously following the reward announcement, they said.
"It is believed that this image was taken some time in the mid-2000s, but that the individual depicted may have information that would help us progress our investigation," Strike Force Aramac lead investigator Detective Chief Inspector Bell said.
"It is our hope that someone in the community may recognise this man so we can speak with him and ensure all possible avenues of inquiry are followed through.
"As always, we continue to encourage anyone in the public that may have information about Revelle's disappearance to come forward and speak with police, so that we may finally provide answers to her family,"
The model and dancer's half sister Suellen Simpson said earlier this year she was hopeful the re-investigation would deliver answers on what happened to Ms Balmain "so that I may finally put her to rest".
"For many years, our family worked tirelessly to find out what happened to my sister - but sadly both our mother and Revelle's father, Ivor, passed away without ever knowing what happened to their little girl," Ms Simpson said.
"Losing someone that is close to you - you're never the same person again. I truly hope this reward will prompt someone to come forward with information that will help police find those responsible for Revelle's disappearance."