The case called at a virtual hearing at the High Court in Glasgow earlier.

Iain Paterson KC, defending, said: "He is pleading not guilty to the charge.

"This is a troubling case - there is no getting away from it. The situation is we are still looking into his mental health issues.

"We have instructed Prof Baron Cohen to provide information on whether Mr Rattray has autism which might link it to a mental health defence - whether his responsibility was diminished regarding this particular crime."

He added: "I don't have a date for which he will provide a report but we will get one in the next couple of months.

"The case has been ongoing for some time and for the family, we need to progress matters and I ask that a trial be fixed."

Dr Gomo was found fatally injured on the street and was treated by paramedics at the scene, but never recovered.

At the time, Police Scotland acknowledged that her death had caused great shock throughout Dundee.

She was originally from Mutare in eastern Zimbabwe, had graduated with a PhD from Dundee University, and had recently started working for Scottish Water.