A Titanic deck plan owned by an elderly couple who were depicted in the hit movie lying in bed together as the ship sank is set to sell for £50,000.

Ida and Isidor Straus drowned side by side in the disaster after she refused a place on a lifeboat to remain with her husband.

Witnesses stated the couple sat on deckchairs and held hands when they were washed into the sea as the Titanic sank.

But in the 1997 movie Titanic, starring Kate Winslet and Leonardo DiCaprio, they were shown cuddling up together on their bed.

The deck plans were only handed out to the 324 first class passengers when they arrived on the liner in Southampton on April 10, 1912.

It is believed only three of them exist today, two in private collections and this one now on the open market.

It was owned by the Straus’s maid Ellen Bird who survived the disaster in which 1,495 people died.

She kept hold of the 41x29 inch plan for the rest of her life and it is now being auctioned by the current private owner.

Despite its age the piece of tissue paper has remained in one piece over the last 99 years.

Andrew Aldridge, of auctioneers Henry Aldridge and Son of Devizes which is selling the plan said: “This represents the zenith of collectables pertaining to Titanic.

“Isador Straus was one of the wealthiest people on the ship and original material relating to his and his party’s time on board Titanic is practically non-existant.

“To have something directly related to Straus which was on the ship is a collector’s dream.”

The deck plan, that folds down to a booklet, is headed ‘White Star Line, Southampton- Cherbourg-New York Service, First Class Accommodation.’ The reverse shows the layout of the top five decks that made up first class and facilities like the restaurants, swimming baths, gymnasium and squash courts.

Each room is numbered in red ink with beds, wash basins and wardrobes inside all marked.

There are still pencilled notes made by Miss Bird who marked her room which was opposite the Straus’s stateroom which had its own bedroom and separate sitting room.

Mr Straus, 63, was a businessman who owned the Macey’s department store in New York.

He and his family were returning to America following a holiday in Europe.

After the 45,000-ton liner struck an iceberg at 11.40pm on April 14, in the north Atlantic many first class passengers were helped into lifeboats.

At first Mrs Straus, 63, joined Mrs Bird in lifeboat eight before getting out to be with her husband, reportedly saying: “We have lived together for many years. Where you go, I go.”

Her body was never recovered.

The auction takes place in Devizes on October 29.