John Douglas Bowie, 72, has pleaded not guilty to murdering Roxlyn Bowie, who was 31 when she vanished from their Walgett home in northern NSW 40 years ago.
The Crown alleges he killed the mother of two children on or about June 5, 1982 so he could have an unfettered relationship with another woman.
Her body has never been found.
In the NSW Supreme Court on Thursday, prosecutor Alex Morris read to the jury notes of a police interview on April 24, 1988 with Gail Clarke, who has since died.
The divorced woman said she met Bowie in his capacity as an ambulance officer in the May school holidays in 1982 when she was staying in a caravan on the banks of the Barwon River at Walgett.
She said they formed a relationship and went out a number of times in his van, including once to the Walgett RSL club..
"She was previously informed by John Bowie that he and Roxlyn led different lives, and she had a boyfriend," the notes said.
On the RSL visit, Bowie pointed out a woman and a man telling Ms Clarke it was Roxlyn and her male friend.
She was unable to give police a description of them.
She said she continued to see Bowie for the duration of the holidays before returning to her Sydney home.
Some weeks later he phoned her and told her he was coming to Sydney.
He came to her home towards the end of June 1982 and told her his wife had left him and suggested he move in with her.
Ms Clarke said she refused his request, but saw him on a number of occasions before terminating the relationship after two to three weeks and never saw him again.
She said she had gone with him to his in-laws' home and met his two children a number of times.
They appeared to be well cared for, although she said she was surprised the daughter made no mention of her mother.
"She also said that Bowie did not discuss his wife or her whereabouts other than saying she had left him."
When Bowie arrived in Sydney, she said he was extremely keen to form a serious relationship but she never entertained the idea.
Mr Morris has told the jury the Crown was not in a position to say precisely how Roxlyn was killed.
But he said a "possible way Mr Bowie disposed of his wife's body was by feeding her to a number of pigs at the pig farm he had been involved with".
His barrister Winston Terracini SC has told the jury while the defence was not saying Bowie was a "perfect fellow" regarding his adultery and behaviour towards his wife, his case was he was not guilty of murder.
The trial continues before Justice Dina Yehia.