A Ma Soeur, controversial French director Catherine Breillat's exploration of childhood sexuality, has been passed uncut by the British Board of Film Classification (BBFC) despite misgivings about some of the film's sexual content.

According to a statement, the BBFC took legal advice about some of the film's sexual scenes, particularly those involving a 13-year-old actress in which "sexual activity was inferred".

Under the 1978 Protection of Children Act it is illegal to show indecent photographs of a child under the age of 16.

The film, released in the UK by Metro Tartan on Dec 7, tells the story of two sisters - the eponymous "fat girl" of the film's English-language title - and her beautiful older sister Elena, who loses her virginity on a family holiday at the seaside.

"There is no statutory definition of indecency and no defence is available on the basis of the merits of the film as a whole," read a BBFC statement. "However, leading counsel concluded that there is nothing in the film which offends the Act."

"The truth doesn't necessarily lie in what you see," says director Catherine Breillat in the film's UK press notes. "The image is a false witness."