A molecular biology expert says he can’t accept the results of tests that suggest brain matter was in a stain found on Mark Lundy’s shirt.

Professor Stephen Bustin has been given evidence as a defence witness in Lundy’s trial for the murders of his wife and daughter.

He’s been closely looking at tests carried out by a Dutch forensic expert, Dr Laetitia Sajin, who says she found it was probable brain was found in the marks on the polo shirt.

He says the tests, or assays, carried out by Dr Sajin on behalf of Crown prosecutors don’t give him enough data to allow him to give an opinion with absolute certainty.

“I couldn’t call this probable at all, I think there’s an equal likelihood it’s real, it’s not real. Based on the information I have, I cannot say.

“But I would be highly reluctant to accept the results of these assays because they’re so fundamentally flawed in terms of the tech that’s been applied.”

Earlier Professor Bustin told jurors a test bought from a manufacturer to help in the process came with instructions, some of which Dr Laetitia Sijen didn’t follow.

He says there’s no explanation as to why the conditions were changed.