The Titanic, which was built in Belfast, leaving Southampton in April 1912. Picture from Associated Press

A set of rusty keys for a locker on the Titanic that belonged to a cabin steward who survived the disaster are being sold by his family.

The keys are expected to fetch up to £60,000 when they go under the hammer on Saturday in Devizes, Wiltshire.

They belonged to Sidney Daniels, an 18-year-old third class steward who was the last surviving crew member of the luxury liner's doomed maiden voyage.

They are the only known examples for concurrent lockers on the ship and were for F Deck where third-class passengers resided.

Each key has a matching brass tag stamped locker 41 F Deck and locker 42 F Deck on a single ring and were in Mr Daniels's pocket when the ship hit an iceberg and sank in April 1912.

Auctioneer Andrew Aldridge, of Henry Aldridge & Son, said: "These keys are exceptional as they are the only known examples belonging to concurrent lockers.

"Mr Daniels later returned home aboard the Lapland and the keys were in his pocket during his escape and subsequent rescue.

"When war broke out in 1914, he served with the Royal Army Service Corps. He passed away in 1983 aged 89."

Another item being sold on Saturday are a pair of previously unseen photos of Titanic as she leaves Southampton. The photographs are estimated to sell for between £8,000 and £12,000.

The photos, measuring 4in by 5in, were sent from Southampton to Mr F Le Boulanger, a wealthy ship owner, who lived in Mumbles, South Wales.

"As Mr Boulanger was a coal exporter in South Wales and as these photos were sent to him, it is quite possible he may have been involved in the provision of coal to the ship," Mr Aldridge said.

"Since the recipient of the photos was important in the ship industry, the photos may have been taken by one of his associates.

"They represent a rare opportunity for a collector to acquire a pair of photos showing the very start of Titanic's ill-fated first and last voyage."

A third piece of memorabilia for sale is an original clapperboard from James Cameron's multi-Oscar winning movie Titanic.

It has a hinged wooden clap-stick with interleaved black-and-white diagonal lines attached to a Plexiglas slate with lettering from a marker identifying date, 11-22-96, scene, take, film title, Digital Domain, supervisor R Legato, and camera operator J Rider.

"Since clapperboards can be repurposed for other scenes and films they do not typically come to market," Mr Aldridge said.

"This one was gifted to a film student on the set. We are aware of another clapperboard from the film in a museum."

The 11in by 9in clapperboard is estimated to sell for between £3,000 and £5,000.

The Titanic sale takes place on Saturday at Henry Aldridge & Son in Devizes, Wiltshire.