Socialite Maureen Boyce's lover told police she went "berserk" the night before her death because she thought he was having an affair with his elderly aunt, a court has heard.
New Zealand-based doctor Thomas Chris Lang is on trial in the Brisbane Supreme Court after pleading not guilty to murdering the 68-year-old at her Kangaroo Point sub penthouse in 2015.
The court has heard Lang called emergency services on the morning of October 22 after finding Ms Boyce dead in her bed with a knife her abdomen.
Crown prosecutor David Meredith has told the jury they must decide whether Ms Boyce took her own life or if she was killed by Lang in a "jealous rage".