Retired doctor Thomas Chris Lang denies killing lover Maureen Boyce

A retired doctor says he is innocent of murdering his lover, former model Maureen Boyce, who was found dead in the master bedroom of her Kangaroo Point penthouse with a 19cm blade buried to the hilt in her stomach. His lawyer claims she killed herself with the knife.

A retired American doctor says he is innocent of murdering his lover Maureen Boyce who was found dead in the master bedroom of her Kangaroo Point penthouse with a 19cm blade buried to the hilt in her stomach.

Thomas Chris Lang has pleaded not guilty to murdering 68-year-old former model Ms Boyce who was found dead in her bed on the morning of October 22, 2015.

Justice Ann Lyons told the jury the case, which is expected to run for two weeks, is a retrial of Lang who is now 68.

Crown Prosecutor Todd Fuller said during the trial, the jury would hear that a kitchen knife with a 19cm blade had gone through Ms Boyce’s stomach and pierced through her back into the mattress below her.

Maureen Boyce pictured in 1997.

And in 2000.

The prosecution alleges Lang murdered Ms Boyce but defence barrister Ruth O’Gorman said DNA belonging only to Mrs Boyce was found on the blade and there was no medical evidence she had struggled.

“The issue in this trial is whether Ms Boyce was killed by Mr Lang or whether she committed suicide,” Ms O’Gorman said.

“We will submit that the evidence establishes that Ms Boyce killed herself.”

The prosecutor said during the trial, medical experts would give evidence Ms Boyce’s body was found with five “track wounds” from the blade with a single entry point but three separate exit wounds in her back.

A 1969 photo of former model Maureen Boyce.

He said the jury would hear two of the tracks had been made with the blade facing upward and the knife was “turned 180 degrees” with the blade facing down in three other stab wounds.

Mr Fuller said a medical expert would tell the jury the stab wounds were “inconsistent with these injuries being self-inflicted”.

The court heard Lang and Ms Boyce had first met more than 30 years before her death when she was visiting the United States and unbeknownst to Lang, she left the country pregnant with his child and raised the boy with her husband Graham Boyce, also a medical practitioner.

The court heard Lang only found out about his son in 2013.

Thomas Chris Lang denies killing Ms Boyce. Picture: Marc Robertson

On the night of her death, the pair had gone out to dinner while a real estate agent showed prospective buyers through the $3.5 million Kangaroo Point sub-penthouse apartment.

Mr Fuller said Lang told police that Ms Boyce suffered from mental health issues and had become upset when she was told the buyers were not interested in the property.

Pictured in 1972.

And in 1968.

He said the pair had also squabbled that night over “suspicious” text messages and communications they had each had with other people that they both claimed were evidence of the other having an affair.

He said Lang told police Mrs Boyce had flung her iPhone from the 20th floor apartment.

The trial continues.