Ancient human remains removed from a crypt in a Highland cemetery were not those of notorious Jacobite supporting clan chief, but a headless woman, according to experts.

Official accounts maintain the remains of Simon Fraser, Clan Fraser chief or “The Old Fox”, were buried under a chapel floor in the Tower of London following his execution.

But the clan has maintained Mr Fraser, the 11th Lord Lovat, was “intercepted” by his own supporters and returned to Scotland in the casket.

The mystery deepened following the discovery of a headless body in a damaged lead casket in the cemetery, Wardlaw Mausoleum at Kirkhill, near Inverness.

An expert team led by British forensic anthropologist Professor Dame Sue Black carried out detailed investigations including DNA testing, to determine whether the body is that of “The Old Fox.”

Professor Black, director of the Centre for Anatomy and Human Identification at the University of Dundee, said: “We can say with absolute certainty that these are not the remains of The Old Fox.

“The remains were in poor condition, very wet, in common with remains that have been a long time in a wooden or lead coffin, so in line with what we expected.

“The area of the body most indicative of whether remains are male or female is the shape of the pelvis, and two areas of the pelvis in particular.

“In both areas, these remains were very feminine. There is no way that these were the remains of an 80-year-old six-foot man who suffered from gout and arthritis.

“We estimate these are the remains of a young woman, probably aged 25-35. We understand that there are some possibilities that she might be a member of the Fraser family, and further DNA testing is being carried out.”

The mystery of how the remains of a headless young woman came to lie in a casket thought to have been designed for Lord Lovat remains following the tests.

Professor Black added: “We simply don’t know what happened to the head, but it may be that it has been taken as a trophy many years ago.

“The DNA testing should confirm whether the remains are those of a member of the Fraser family, in which case the casket may well have simply been put to use.

“But if the remains are not a member of the family, then we are faced with more of a poser as to how she came to be buried in the casket.”

The Old Fox is known to readers and TV audiences as the grandfather of Jamie Fraser, the lead character in the television series “Outlander”.

He supported Bonnie Prince Charlie who was defeated at the battle of Culloden and was sentenced to death for treason against the Crown.