A RARE letter from the doomed RMS Titanic is expected to fetch up to £10,000 at auction in Leyburn next month, after it was discovered being used as a bookmark.

The four-page letter, written on the ship's headed notepaper by a woman passenger to her nephew, is dated April 10, 1912 - the day the ship left Southampton.

The letter, which describes the ship in detail, was passed to the nephew's daughter, who lives in Leyburn, and was kept only for sentimental value.

The artefact came to light when the owner visited Tennants' Auctioneers in Leyburn to value a different item, and a comment from valuer Diane Sinnott prompted her to mention it.

Mrs Sinnott recognised the letter's potential value and urged the owner to keep it safe. The letter was found marking pages in a book

It describes the splendour of the Titanic: "It is a vast place, five decks, immense drawing rooms and dining rooms and swimming baths and a gymnasium, and a band playing."

Records show the writer was a first class passenger travelling from Southampton to in Cherbourg. She paid £1 10s for her ticket and was travelling with her sister-in-law, who had brought her two young children. They disembarked in Cherbourg.

Phil Peppiatt, Tennants' books consultant, said: "There has been interest from buyers from the United States, where the biggest collectors are.

"We've never had a Titanic letter before, but this is a really interesting one and I'm sure there are a lot of people who would love to own it."

The letter will be sold at Tennants' on February 25.