A medieval chess piece missing for almost 200 years being being found in a drawer in Edinburgh has sold for £735,000.

The Lewis Chessmen - a famous hoard of 93 objects - were discovered in 1831 on the Isle of Lewis in the Outer Hebrides.

But the whereabouts of five pieces from the collection had remained a mystery.

That became four when a family learned the chess piece their grandfather bought for just £5 in 1964 was one of the missing treasures.

The antiques dealer, from Edinburgh, had no idea of the significance of the 8.8cm piece, made from walrus ivory, which he passed down to his family.

They looked after it for 50 years without realising its importance, before bringing it to Sotheby's auction house in London on Tuesday, when it was sold to an anonymous bidder.

The Lewis Chessmen are among the biggest draws at the British Museum and the National Museum of Scotland in Edinburgh

Alexander Kader, Sotheby's co-worldwide head of European sculpture and works of art, said: "This is one of the most exciting and personal rediscoveries to have been made during my career.

"It has been such a privilege to bring this piece of history to auction and it has been amazing having him on view at Sotheby's over the last week - he has been a huge hit.

"When you hold this characterful warder in your hand or see him in the room, he has real presence."