Chris Dawson's murder trial has heard his first wife Lynette was seen outside a Sydney hospital up to six months after she disappeared from their northern beaches home in January 1982.
The court was on Tuesday played a video recording of a police interview from March 2019 with Mr Dawson's late brother-in-law Ross Hutcheon.
Mr Hutcheon, who was married to Chris Dawson's sister, who is also called Lynette, died six weeks ago.
In a video, he told officers he had been travelling west along Victoria Road when he saw Ms Dawson standing at a bus stop outside what was then the Gladesville Hospital.
"She looked just like the Lyn that I knew — same colour hair, same hairstyle, same glasses. No obvious attempt to disguise herself," he said.
"The other thing that convinced me … was the fact that it was opposite the hospital and she was a nurse."
The Crown alleges Chris Dawson murdered his first wife in order to pursue a relationship with the family's 16-year-old babysitter, who was also a student at Cromer High School where Mr Dawson taught physical education.
He has always denied any involvement in Ms Dawson's disappearance and claims she left voluntarily.
There have been no verified sightings of her since.
In the 2019 interview, Mr Hutcheon told police that once he passed the woman he believed to be Ms Dawson, he continued driving for about half a kilometre, then doubled back to speak to her.
"I did a U-turn, and by the time I got back to the bus stop she was gone," he said.
He said he had relayed the information to two police officers who came to speak to him about the disappearance "something like" three to six months after the disappearance.
But when shown police records that indicated the interview was in fact conducted more than 15 years later in 1999, Mr Hutcheon conceded that might have been the case.
In another tape played for the court, this one of a 2020 committal hearing, Crown prosecutor Craig Everson suggested to Mr Hutcheon that in the 1999 interview he actually told police he had had "no contact with Lynette Dawson since her disappearance".
"I had visual contact with Lyn Dawson, not verbal contact," Mr Hutcheon responded.
Mr Hutcheon said as well as telling police and his wife about the sighting, "three or four years" before 2019, he made the decision to disclose it to Chris Dawson's brother Peter.
"Things started to get very serious when [Chris Dawson] was charged and whatnot, and I thought I'd better do something about it," he told the officers.
He added: "I don't think Chris would have done something like that."
At the 2020 committal hearing, he explained the decision further.
"I had already spoken to the police,," Mr Hutcheon said.
"As far as I was concerned, the police had every detail about the sighting.
"I thought the system knew … I thought it's about time I spoke up because it didn't appear as though my evidence had been looked into.
"I made a very, very, very big mistake by not stopping my car and speaking to Lyn … I should have told everybody at the time but I just didn't understand the implications of the whole issue."
The court was also played an audio recording of a phone call made by Mr Hutcheon's wife Lynette to Chris Dawson on the day of the 1999 police interview.
In the call, Mr Dawson and Ms Hutcheon discuss the visit and who else the police might be preparing to contact in relation to the disappearance.
In the witness box on Tuesday, Mr Everson asked Ms Hutcheon why she had not taken that opportunity to mention the alleged sighting of Lynette Dawson at Gladesville.
"It didn't come up," she responded.
"I didn't tell him everything else that was in the conversation. If I'd known it was going to come up now I would have listed everything that was said but... it wasn't important to me to tell him at that stage."
She told the court that she heard about numerous reported sightings of Lynette Dawson in the weeks and months after her disappearance, including from her aunt.
"My husband had seen her and I had heard that other people had seen her. I thought she had been seen by people that knew her," she said.
The trial before Justice Ian Harrison continues.
