Adele Exarchopoulos and Lea Seydoux in a scene from <i>Blue is the Warmest Colour</i>.

Adele Exarchopoulos and Lea Seydoux in a scene from Blue is the Warmest Colour.

The French author of the book that inspired this year's Palme d'Or winner at the Cannes Film Festival has slammed the movie's director for turning her novel into a work of "porn".

Julie Maroh, 27, is not a fan of Abdellatif Kechiche's acclaimed Blue is the Warmest Colour, which chronicles the love story of two lesbians and features graphic sex scenes.

Maroh took to her blog after the film won the Palme d'Or in May and wrote: "This was what was missing on the set: lesbians".

She said Kechiche and his stars, Adele Exarchopoulos and Lea Seydoux, were "all straight" and call the film a "brutal and surgical display, exuberant and cold, of so-called lesbian sex, which turned into porn".

Maroh joins a chorus of critics, who have accused Kechiche of making a voyeuristic film that projects male fantasies of lesbian sex, and says the director ignored her requests for feedback while he was making the movie.

The author's critically acclaimed 2011 novel will be published in English in 2013. The film will hit European cinemas in October.

No Australian release date has been announced.

WENN