The current monarch of the tiny Mediterranean state and his sisters Princess Caroline and Princess Stephanie said in a statement released by the royal palace of Monaco that the film project "Grace of Monaco" contained "historical untruths" and that some parts were "purely fictional".

The statement was intended to shoot down a story in French magazine Paris Match, which said the Monaco royals had been reassured by producers about the credibility of director Olivier Dahan's film project.

"Having in no way been associated with this project, Their Highnesses were quite surprised when they received the script," said the statement emailed to Reuters on Thursday.

"The Palace had submitted many requests for changes to the producers of the film, not all of which were taken into consideration."

The star of such Hollywood classics as "To Catch a Thief" and "High Society" as well as Alfred Hitchcock's "Rear Window" and "Dial M for Murder" became Princess Grace when she married Albert's father Prince Rainier of Monaco in 1956.

The palace said it would not tolerate the suggestion in Paris Match that Albert and his family supported the film.

"Consequently, the Princely family wishes to emphasize that this film is by no means a biopic," the statement said.

"It recounts one page, rewritten and 'glamorized' for no good reason, in the history of the Principality of Monaco and their Family which includes both major historical untruths and a series of purely fictional scenes."

The film is billed by production company YRF Entertainment as a story of the newly minted Princess of Monaco proving herself against all odds by leading her adopted country in its struggle against France when it tries to take over Monaco.

Prince Rainier is played by Tim Roth. The film is due out in 2014.

(Reporting by Matthias Galante and Paul Casciato, editing by Patricia Reaney)

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