In his final report before retiring as head of the British Board of Film Classification, Ferman has criticised violence in films for its dangerous impact on vulnerable viewers.

"I worry that violence has so little meaning," said Ferman.

"That younger cinema-goers take the view that 'violence is cool', a view which seems to me to be simply an excuse for not empathising with the victims."

Lethal Weapon 4's distributers cut the film for the UK audience

In the wake of recent school shootings in America, Ferman condemned "dangerously imitable violence".

"In my view it functions like a drug, like the pounding beat of rock music which keeps the serotonin levels up," he said.

The outgoing director's report also discloses that even the latest Disney cartoon Mulan had to have a "vicious head-butt" scene removed before it was granted a U-certificate.

But the BBFC's annual report also reveals that only 3.6% of films needed cuts in 1998, which is the lowest percentage on record and compares to 40% 25 years ago.

But Ferman insisted: "My instinct is still to reduce the level of violence in action adventure films, simply in order to have less of it."

In contrast the BBFC report praised films like Steven Spielberg's Saving Private Ryan, which "explored violence rather than exploiting it".

Sexual violence also remains a major concern in the report which refers to Naked Killer 2, a Hong Kong thriller, which had to be submitted to the censors three times, and cut by 11 minutes before it could be passed.