The fingerprints of a former New Zealander accused of murdering a Brisbane socialite were "nowhere" on a knife found fully embedded in her stomach, a court has heard.
Thomas Chris Lang has been charged with the murder of his former partner, Maureen Boyce, after she was found dead in her Kangaroo Point penthouse in the early hours of October 22 in 2015.
Defence lawyer Terry O'Gorman summarised the prosecution case against his client at the start of a committal hearing in the Brisbane Magistrates Court on Thursday.
The court heard Lang told police Boyce had asked him to sleep in another room because of "snoring issues" and went to check on her when he rose at about 5.30am.
"The prosecution case is that Ms Boyce was found by Mr Lang in bed, deceased ... with a knife fully embedded in her stomach," he said.
"The prosecution case is that Mr Lang's fingerprints are nowhere on that knife."
Analysis of post-mortem evidence suggested the wound could have been self-inflicted or the result of someone else stabbing Boyce, he said.
Lang later told police Boyce had high expectations she would find a buyer for the spacious unit after an inspection on October 21 and was "considerably upset" when it failed to sell, it was heard.
There was also evidence she'd had phone conversations with two friends and told them she was depressed, O'Gorman said.
He said one was high-profile Brisbane businesswoman Sarina Russo with whom Boyce spoke the night before her body was discovered. Russo is expected to be called as a witness in October.
Lang and Boyce first met in the US about 30 years ago and began a relationship, but "resumed contact" in 2013 when Lang was living in New Zealand and they would take trips to visit each other.
The court heard a key issue would be differing opinions held about Boyce's mental health around the time of her death.
Boyce's former acquaintance Kenneth McAlpine also gave evidence that he recalled getting a voicemail on October 21.
He said she said she had friends visiting from New Zealand but one man wouldn't leave and she didn't know what to do about it.
"And, in a light-hearted manner, said maybe I need you to come over and get rid of him?" O'Gorman asked, drawing from the man's police statement.
"Correct," McAlpine said.
O'Gorman quizzed Detective Sergeant Sean Webster about topics including the duration of Lang's interview with police, which lasted eight hours, and his access to a lawyer.
The hearing before Magistrate Belinda Merrin continues, with Boyce's husband and son expected to appear on Friday.