Lt Cmdr Balme recalls the day he led the boarding party onto the German submarine

Lt-Cdr David Balme, 78, took part in a daring mission in the Atlantic in 1941 which led to the capture of the Enigma cypher machine from a German submarine. It was hailed as a turning point in the war.

The news that Hollywood was planning to make a film based on the story - only crediting Americans with the capture instead of the British - upset many British veterans including Lt-Cdr David Balme, who led the boarding party onto the submarine.

The Enigma machine was vital cracking Hitler's secret codes

More than 70 UK MPs signed a petition urging the film's producers to acknowledge the British Royal Navy.

When the film's executives found out they quickly offered Lt-Cdr David Balme a walk-on part in the movie and offered to also include a caption acknowledging that the capture of the Enigma machine in 1941 was actually carried out by the British.

Lt-Cdr David Balme said: "They are going to put full credits at the end of the film about the real events.

"They were very sorry they had upset the British and they are trying to put it right. I'm glad the British will get the credit we deserve."

Harvey Keitel is to star in the film

The capture of the enigma machine and cracking of its code at the British intelligence centre in Bletchley Park saved thousands of Allied warships from destruction by German U-boats and helped the Allies to win World War II.

The $90m film, U-571, starring Harvey Keitel, Jon Bon Jovi, Bill Paxton and Matthew McConaughey relocates the Royal Navy's heroics from the Atlantic to the Mediterranean as well as showing the capture being carried out by an American unit.

The film's producers even flew Lt Cmdr Balme to Malta at their expense to meet the film's cast and asked him to describe the real-life operation that inspired the film, in which his role is played by McConaughey.

"They were very nice people and wanted to hear how it was done.

The BBC's Virginia Eastman: "The plot has been altered to allow the Americans to save the day"

'It's going to be one of those all-male movies in the Guns of Navarone style. It's going to be a very good movie. They hope it will be as big as Titanic," he said.

Lt Cmdr Balme's non-speaking walk-on part will be filmed on the Cornwall coast.

"Some time this month I will be going down to Land's End where they will be filming a life-raft coming in with survivors.