More videos showing hardcore sex have been approved by film censors in the last month than in all of last year, it was revealed yesterday.

The British Board of Film Censors last month brought in new guidelines which allowed more explicit scenes of real sex to be shown on films sold through licensed sex shops to adults.

One leading porn film distributor yesterday predicted a rise of up to 50% over the next year in the number of videos sold because the rule relaxation will allow stronger material to be shown.

The rise in the number of titles classed as R18 has been mainly caused by a backlog which built up while the new rules were being drafted, said the board.

In addition, video distributors have starting resubmitting films so as to have scenes reinstated which were cut under the old rules.

Guidelines were changed following a high court ruling against the board for refusing certificates to seven sex films.

Rather than continue the appeals process, the body opted to alter its rules.

Previously banned material which can now be shown includes close-up shots of penetration by penis, finger, tongue or sex toy, ejaculation, oral-genital contact, and masturbation.

Since the changes on July 18 which moved Britain's censorship laws closer to the rest of Europe, the board has given a further 23 R18 ratings, which is two more than were given in the whole of the previous year.

The average number of R18s handed out over the past nine years is around 22, which rep resents less than 1% of the 5,000 video titles handled annually by the board.

An R18 classification is given to a film during which real sex is shown, while simulated sex acts will usually get an 18 rating.

Distributors of hardcore porn films are preparing for increased profits as a result of the relaxed rules.

Gary Campbell, a director of Prime Time, the second largest UK distributor, said the more liberal censorship laws could curtail the black market for sex videos, which was seven times larger than the legal market.

"The punters for years wanted stronger material. Now the material is in line with Europe, demand is going up, which is good as it takes it away from the black market."

Sue Clark, spokeswoman for the board, said no videos had been denied an R18 rating since the new guidelines started: "The industry knows what the guidelines are. They don't put any videos in to be turned down, because it's a waste of their money."

She added that the initial rise in numbers had been anticipated as film companies held back their titles until the situation was clarified.

"We would have expected this because of the backlog which built up as we waited to get the new guidelines through. We deal with over 5,000 titles a year and these videos are only a tiny part of that work."

• A series of films which were refused certificates is to be screened at the Institute of Contemporary Arts in London later this year as part of a debate on the future of censorship organised in collaboration with Channel 4.