*Rare Sherlock Holmes manuscript for auction.

A handwritten copy of one Sir Arthur Conan Doyle’s final Sherlock Holmes stories, The Adventures of Three Gables is expected to make £250,000 at a Sotheby’s New York auction.

Edinburgh University, where Sir Arthur studied medicine, is expected to be among those bidding for the rare manuscript.

Marsha Malinowski of auctioneers Sotheby's said: "Conan Doyle had extraordinarily clear and beautiful writing.

"He was the sort of writer who would not put pen to paper until he had thought out clearly what he wanted to write.

"So, although there are more than 100 amendments, they are usually minor changes such as clarification or emphasis."

This copy of Three Gables, bound in vellum, was once owned by the Marquis of Donegal and has been in private collection since the 1970s.

Sotheby’s have estimated it will fetch $350,000 to $500,000 when it goes under the hammer on 21 June.