The release of Howard Marks biopic Mr Nice later this year is bound to cause some controversy, but that won't bother the man himself.

Marks was one of the biggest drug smugglers of his time in the 1980s, using 43 aliases, 89 phone lines and 25 companies as he reportedly controlled almost 10 per cent of the world's dope trade.

He was finally caught and imprisoned in America in 1988, serving seven years in one of their toughest prisons before being released and then publishing his best-selling autobiography Mr Nice in 1996.

He sold the rights to the film not long after that but has only now been made starring fellow Welshman Rhys Ifans as Marks.

Although some campaigners are bound to vent their anger at a film glorifying one of the most prominent supporters for the legalisation of drugs, Marks insists he doesn't listen to them.

"There will be always be that element but I have never taken much notice of them," he says.

"I think it will do well because I liked it but I am probably not he best person to ask.

"I sold the film rights about 13 years ago but it took a while for it the subject to become PC shall we say.

"The consulted me and I answered a few questions for them but I had no other role and had no real say in it at all.

"Rhys has portrayed me very well.

"We have known each other for about 13 years and it is something we always hoped would happen and have been trying to get done since we first met, just after he had been sacked as the Super Furry Animals' lead vocalist."

Marks brings his comedy show to the Halfmoon a week on Friday, in which he talks about his past and a lot of the issues raised in his book.

He will also be DJing after, with Wimbledon band Gold Teeth providing the support beforehand.

"It's a comedy night and not a lecture that dope should be legalised," he says.

"It's basically a stage manifestation of the stuff I have written in the past.

"The audience tends to be 18 to 25 year-old dope smokers, which, when it first started to happen, I found astonishing but I have kind of got used to it now."

As for his stance on drug legalisation, Marks is still confident that his campaign will eventually succeed, but not that he will be around to see it.

"I am still for it," he says.

"I am for every drug really, not just cannabis.

"I think it will happen but whether I live to see it happen I do not know.

"It's always three steps forward and a couple backwards but that is the nature of change really.

"The government has to keep it illegal because of the United Nations convention, every nation in the UN is obliged to keep it illegal but it is up to the nations what penalty to impose.

"Holland for example has no penalty while Singapore decide to hang you."

An Audience with Howard Marks plus special guests, Halfmoon, Lower Richmond Road, March 26, 8.30pm, £20. Call 020 8780 9383 or visit halfmoon.co.uk.