A forensic examination of the contents of a coffin is to be carried out in a bid to confirm they are the remains of a notorious 18th Century clan chief.
Nicknamed the Old Fox, Simon Fraser, 11th Lord Lovat, was a Jacobite sympathiser who did deals with the cause's enemies.
He was executed in London after supporting Bonnie Prince Charlie.
Scientists, led by Dame Sue Black, plan to carry out the study at Highlands mausoleum next month.
'Who's in our crypt?'
After being beheaded in 1747, Lord Lovat's body was buried under the floor of a chapel at the Tower of London.
However, according to the clan Fraser, his body was intercepted by his supporters and taken back to Scotland where it was laid to rest in his family's mausoleum.
A body, minus the head, is in a lead casket inside Wardlaw Mausoleum at Kirkhill, near Inverness.
The trust that looks after the historic site hopes forensic science can prove that the remains are those of the clan chief.
Erik Lundberg, of the Wardlaw Mausoleum Trust, told BBC Radio Scotland: "Finally, we might get some answers to who lies in our crypt."
The Old Fox is known today by readers and TV audiences as the grandfather of Jamie Fraser, a lead character in the Outlander books and television drama.
'Laughing your head off'
The books and the TV show have brought hundreds of visitors to the Wardlaw Mausoleum.
The clan chief, the last person to be beheaded in Britain, is recorded in history as a charmer who was prepared to switch sides during and around the times of the Jacobite uprisings.
But the last of those risings, in which he supported Bonnie Prince Charlie, ended in defeat for the Jacobites at Culloden in April 1746. The following year Old Fox was executed at Tower Hill.
It is said that several people who had gathered to watch the beheading died after the scaffold they were on collapsed.
Lord Lovat found this incident funny and is said to have been so visibly amused when he was executed that his death led to the phrase "laughing your head off".