A letter from a surgeon aboard the doomed Titanic is on its way back to Belfast thanks to a mystery donor.

The unknown benefactor has ensured the letter from assistant surgeon Dr John Simpson is to return to his hometown.

The document was on sale for a reserve price of $34,000 at the New York auction with Simpson’s family fearful it would end up in a private collection.

Dr Simpson had penned the letter to his mother just days before the ship sank.

The family’s campaign to bring the letter back to his native city, ahead of the 100th anniversary of the tragedy, proved successful when the anonymous donor bought it after it failed to reach the reserve and handed it back.

Eye witness accounts say that the 37-year-old Simpson stood with fellow officers on the deck of the Titanic as it went down and made no attempt to board the lifeboats.

Great-nephew Dr John Martin told the Press Association that the family are happy that the letter is on its back way to Northern Ireland where it ‘belongs’.

“I’m absolutely delighted,” said Dr Martin. “I’ve never actually seen the original letter itself as it was last in Belfast in the 1940s before Dr Simpson’s son moved away.

“So for it to be on its way back is just amazing and so appropriate now just ahead of the 100th anniversary of his death. We are so thankful to the benefactor.

“The letter had been passed down several generations of the family and the plan was always to have it placed in a permanent Titanic exhibition in Belfast.”

The letter was handed over to a Dutch collector by Simpson’s daughter-in-law 15 years ago when it was due to become part of an exhibition but it then vanished.

“We thought it was gone for good until we heard it was to be sold at Philip Weiss Auctions in New York,” added Dr Martin.

“The item failed to reach its reserve price at the sale earlier this month, enabling the benefactor to step in and purchase it for an undisclosed sum.

“The letter will soon be back in Belfast, with the intention of putting it in a public exhibition before the April anniversary of the disaster.”