A huge chunk of the likely audience for Brüno, Sacha Baron Cohen’s new film about a gay Austrian fashion journalist, will not see it on the big screen after a surprise 18 rating was announced yesterday.

The British Board of Film Classification ruled that strong sexual content in three scenes made one of the summer’s most widely anticipated films unsuitable for the 15 certificate needed to generate a blockbuster audience.

The British comic’s two previous efforts, Ali G Indahouse and Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan, were both rated 15.

Baron Cohen attended the British premiere of Brüno at Leicester Square last night in character. The film, like Borat, is a mock documentary in which Brüno, the outrageous lead character played by Baron Cohen, exposes the bigoted views of unsuspecting real people.

But where Borat catapulted a gauche, anti-Semitic Kazakh journalist into middle America to examine attitudes to race and cultural values, Brüno tackles homophobia and the legacy of Austria’s Nazi past.

The 18 rating will reduce Brüno’s cinema takings in Britain, where Borat made £23.9 million. Only two of the top 100 films at the box office were 18s: Hannibal in 62nd place and Se7en at 78. Borat is placed at 52.

A re-edit helped to avert a worse fate in the United States where Brüno was originally awarded a NC-17 rating, meaning that most American cinemas would not have screened it. A revised version was later passed as an “R”, restricted to over 17s or younger teenagers accompanied by an adult.

The same revised version, where black circles were inserted to cover body parts, was presented to the BBFC yesterday.

Under the British censor’s system which unlike their American equivalent is based partly on public consultation this was insufficient to earn a lower rating.

A spokesperson said: “We felt that made it worse not better in some scenes because you could not tell what was acted out.”

In two of the three most extreme scenes the sex was faked: an outrageous love scene between Brüno and his pygmy boyfriend and a sequence where Brüno mimes a sexual act in explicit detail.

However a third, filmed at a real swinger’s party, shows unsimulated sex.

One film stalwart who saw an early industry screening of the film reported that there was “a lot of squirming in seats”.

“It’s absolutely an 18 film. It could have had a 30 certificate.”

Only 48 of the 639 films passed by the BBFC last year received 18 certificates, only seven of them predominantly because of sexual content.

Universal, the studio which signed Baron Cohen up for an alleged $22million to make the film, rejected several proposed cuts that would have qualified it for a 15 rating.

Conor Dignam, editor of the industry magazine Screen International, suggested that they may be gambling that the notoriety of an 18 certificate will merely build anticipation amongst a teenage audience and guarantee an even longer commercial life on DVD and television.

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