A book alleged to be bound in the skin of a Jesuit priest executed over the 1605 Gunpowder Plot is due to be sold at auction.
The 'spooky' book labels Father Henry Garnet as a traitor
The macabre lot, deemed "a bit spooky" by the auctioneer, has the mysterious image of a face on the cover, said to be that of Father Henry Garnet.
Auctioneer Sid Wilkinson of Doncaster said the face shows the haunting presence of a man falsely accused.
The book, dating from 1606, is expected to fetch several thousand pounds.
Mr Wilkinson said the book - wordily entitled 'A True and Perfect Relation of The Whole Proceedings against the Late most barbarous Traitors, Garnet a Jesuit and his Confederats' - has not been subjected to DNA testing.
But, the auctioneer said, there is very good reason to believe the cover is human skin.
"It's conjecture, but it's also quite good conjecture as these books are known to exist," Mr Wilkinson said of the eerie binding.
Other examples of human skin bindings exist at Harvard University and several medical texts are also bound in the same material.
"Actually up until the 19th century, books were being bound in human skin," he said.
The strange wrinkling of the cover that forms the face of a man remains the greater mystery, Mr Wilkinson said.
"It is said to look like Henry Garnet, who is believed to have had rather large eyes and it is a bit spooky. It doesn't seem to be manufactured in any way," he said, adding that he could not rule out the chance that it was "a pure coincidence of wrinkling over time".
Henry Garnet was accused of treason as part of the 5 November 1605 Gunpowder Plot, although evidence suggests that while he knew of the plans, he urged the Catholic conspirators not to resort to violence.
Garnet's knowledge of the failed plot to kill King James I by bombing the opening of Parliament came via another priest who heard it in confession and he was therefore bound to silence.
The cover of the book appears to bear the image of a human face
Mr Wilkinson said there are tales of the priest's image appearing elsewhere, including in the straw collected from the basket where the priest's head was placed after his execution in May 1606.
Mr Wilkinson, who specialises in early oak furniture, said no guide price has been set for the book, as it is such a rare lot.
"We have nothing to compare it to but judging by all the interest that's been created I think we could see it sell in the low thousands," he said, adding a film script on Garnet's life is reportedly in the works.
The auctioneers came across the book while cataloguing furniture for a wider sale due to take place Sunday.