Forensic experts have told a Qld court cuts on Gerard Baden-Clay’s face look like fingernail scratches and that blood was found in his wife’s car.

Accused wife killer Gerard Baden-Clay told police he cut himself shaving the morning his wife vanished, but a forensic expert says the marks on his face look more like fingernail scratches.

Baden-Clay’s murder trial has also heard that traces of blood were found in his wife Allison’s car.

The Supreme Court in Brisbane heard that police who responded to Baden-Clay’s emergency call on April 20, 2012 to report his wife missing were immediately suspicious of red marks on his face.

“Gerard, I have to ask this question, those two marks on your face could be consistent with having been scratched,” Senior Sergeant Narelle Curtis said in a recorded interview that was played to the court on Wednesday.

“No, it’s not, I cut myself shaving … I was rushing because I needed to get all the girls up,” Baden-Clay replied.

But forensic expert Margaret Stark from NSW police’s clinical forensic medicine unit, who studied photographs of Baden-Clay’s injuries, said while she couldn’t completely rule it out, they were not consistent with cuts from his razor.

“These injuries are typical of fingernail scratches,” the forensic doctor of 25 years’ experience told the court via video link from Sydney.

“It’s not diagnostic, it’s not 100 per cent, but in my experience this is a very typical presentation of being scratched by fingernails.”

A forensic police officer, who tested the razor for blood, said there was no positive reaction but agreed blood can be washed away.

However the officer, Detective Carl Streeting, said a chemical test conducted in mid-May 2012 on a Holden Captiva from the Baden-Clay family home showed a “transfer blood stain” on an inside panel of the boot.

“Some force would have to have been applied to make it transfer, I can’t say how much,” he said.

The court has previously heard the car was usually driven by Mrs Baden-Clay.

Baden-Clay told police on April 20, 2012 that he and his wife had discussed his past infidelity the previous night but the talk had ended on a positive note.

He’d gone to bed and left his wife watching TV and when he woke up in the morning she was gone, he said during the interview at his home in Brookfield in Brisbane’s west.

The former real estate agent’s voice remained composed throughout the lengthy recorded interview until he described how he’d repeatedly tried to contact his wife by phone, and his voice cracked.

Senior Constable Cameron Simmons said that Baden-Clay had appeared calm and composed during the interview.

“He didn’t shed a tear,” he told the trial.

Mrs Baden-Clay’s body was found 10 days later on a creek bank in Anstead in Brisbane’s west.

An autopsy was unable to determine what caused her death.

The trial continues.