Executives said they did not know how to market the film

In an interview with BBC Radio 4's Front Row, Lord Attenborough, 77, said US distributors were to blame.

He said they had ignored Grey Owl because they did not know how to market a movie without the usual high-powered ingredients.

"No company has bought it for distribution. They say they don't know how to sell it - and by that they mean it doesn't have the supposed prerequisites of commercial success," Lord Attenborough said.

He added: "It does not have a sufficient scale, does not have sufficient special effects and does not demonstrate or illustrate either the pornography of violence or sex."

Lord Attenborough has been an accomplished actor and film-maker for 40 years.

Among his most memorable movie-making achievements are the films Cry Freedom and Gandhi - for which he won two Academy Awards.

I don't accept the pornography of violence under any circumstances

Lord Attenborough

He told Front Row that Grey Owl - scripted by Gladiator screenplay writer William Nicholson - initially received a positive reaction from US movie executives.

But despite acknowledging its quality, the executives would not consider trying to release it to cinema audiences.

"They look at the movie and say 'what a beautiful movie, gosh it's a lovely movie, I really enjoyed it'," said Lord Attenborough.

"'But we can't sell it', they say, 'We don't know how to market it'."

He added that he had nothing against sex in movies as long as the classification system protected children from explicit content.

However, when it came to violence, Lord Attenborough said he was not prepared to compromise his art.

"I don't accept the pornography of violence under any circumstances and if that's a prerequisite to getting a distribution in America, I'll accept the non-distribution," he said.