The author of the graphic novel on which the winner of the Palme d’Or at this year’s Cannes film festival was based, has slammed the film, saying that its lesbian sex scenes were “ridiculous”, and compared them to porn.

Julie-Maroh, who wrote the graphic novel Blue is the Warmest Colour, which was adapted into a film directed by Tunisian-born French director Abdellatif Kechiche, before winning the top prize at Cannes last weekend, came down heavily on the film in a blog post.

It was announced on Sunday that the film had won the Palme d’Or, beating the Coen Brothers’ Inside Llewelyn Davis, which won the Grand Prix, the runner up prize. 

Writing on her blog, Maroh slammed the critically acclaimed film, which caused a stir because of its graphic lesbian sex scenes, saying the scenes were not realistic, and criticising the lack of lesbian actors in the cast.

She wrote: “I don’t know the sources of information for the director and the actresses (who are all straight, unless proven otherwise) and I was never consulted upstream… Maybe there was someone there to awkwardly imitate the possible positions with their hands, and/or to show them some porn of so-called ‘lesbians’ (unfortunately it’s hardly ever actually for a lesbian audience).

“Because – except for a few passages – this is all that it brings to my mind: a brutal and surgical display, exuberant and cold, of so-called lesbian sex, which turned into porn, and [made] me feel very ill at ease. Especially when, in the middle of a movie theatre, everyone was giggling.

“The heteronormative laughed because they don’t understand it and find the scene ridiculous. The gay and queer people laughed because it’s not convincing, and [they] found it ridiculous. And among the only people we didn’t hear giggling were the potential guys [sic] too busy feasting their eyes on an incarnation of their fantasies on screen.”

She went on to say that she was representing her personal stance, but that she did not support the “direction” the film took.

“As a feminist and lesbian spectator, I cannot endorse the direction Kechiche took on these matters… I’m also looking forward to what other women will think about it. This is simply my personal stance.”

The story centres around 15-year-old character Adele, played by Adele Exarchopoulos, and her lover Emma, who is played by Lea Seydoux.

Famed director Steven Spielberg, who headed the judging panel, commented on the lesbian drama, which raised eyebrows for its graphic sex scenes, saying they were not an issue, and that it was a “great love story” he felt “privileged” to have seen.

Kechiche said he would consider cutting some scenes, in order to have the film seen by as wide an audience as possible.