Lenkiewicz bought the remains of Ursula Kemp - hanged in 1582 for being a witch - for a reported sum of either £5,000 or £8,000 from a Cornish museum in the late 1990s. He put the woman's skeleton in a lined coffin on the first floor of his library in Lambhay Hill for visitors to see. Large nails had been placed on the skeleton at the points where metal stakes were driven into the body of the 'witch' to stop her spirit from rising.

Ursula Kemp, a midwife in her forties, was tried and executed in Chelmsford, Essex, after being accused of witchcraft by her eight-year-old son. Her remains were unearthed by accident in 1921 and then taken to Boscastle Museum of Witchcraft, where they were later bought by Lenkiewicz.

Although she was tried at Chelmsford, Ursula Kemp actually came from St Osyth, a village on the coast a few miles away.

The skeleton is now understood to be part of Lenkiewicz's estate, which includes the embalmed body of Diogenes, who was discovered in a drawer in the Lenkiewicz's studio.

In an article in the Plymouth Evening Herald, Dr Philip Stokes was quoted as saying: "The skeleton was lying inside the coffin, which was lined with blue material. The skeleton was laid out in the coffin with nails laid beside it at the appropriate points. It was at the far end of the library on the first floor, where the indexer would work. There was nothing special about it, it was just dried out old bones. I was not surprised it was there because Robert has had major projects on death and he was an authority on witches. His library of witchcraft materials was unique. He got a number of skulls from various sources over the years."