London: Howard Marks a prolific British drug smuggler turned bestselling author has died of bowel cancer aged 70 his editor and friends said Monday.

His death on Sunday came 21 years to the day of his release from prison said a statement linked to by his official Twitter account.

Born in a Welsh coal mining village Marks graduated from Oxford University in the 1960s before embarking on an international criminal career spanning two decades that he described in his bestselling 1996 autobiography "Mr Nice".

"'Mr Nice' was above all an adventure story" said Geoff Mulligan his editor at publishers Harvill Secker.

"Around the time of publication a close friend of Howard said to me: 'People are going to think he's made half of this up but I know he left half of it out.'

"Howard led a remarkable life. He was a loving father a kind man a loyal friend and a person of exceptional intelligence."

Marks smuggled hashish in the furniture of Pakistani diplomats moving to London and in the music equipment of fictional British pop groups touring the United States and briefly worked for the MI6 spy agency.

In his book he also described doing business with the Trafficante crime family in the United States and using connections with Irish Republican Army paramilitaries in Ireland.

During the mid 1980s he had 43 aliases 89 phone lines and 25 companies trading throughout the world.

Marks was finally arrested in 1988 and extradited to the United States where he served seven years in prison before being released on parole in 1995.

- 'Modern-day folk hero' -

After his release Marks toured as a one-man show recounting tales from his past and appeared at the Glastonbury festival.

He became a campaigner for the legalisation of cannabis and launched a failed bid for a parliamentary seat in the 1997 general election.

His autobiography was turned into a 2010 film starring fellow Welshman Rhys Ifans and Chloe Sevigny.

Marks had a monthly column in the British men's magazine Loaded which was then edited by his friend James Brown.

Marks was a "true modern-day folk hero" who did "so many funny shocking illegal things" Brown told The Guardian newspaper.

His last book "Mr Smiley: My Last Pill And Testament" will be published in paperback on April 21.

Publisher Robin Harvie of Pan Macmillan said he was a "true original in every sense of the word".

"He worked extremely hard to make sure that his illness didn't get in the way of him telling his last story and as anyone who ever met him knows there was no one quite like Howard for spinning a yarn" Harvie said.

Marks announced last year that he had inoperable bowel cancer. Media reports said he died at his home in south Wales.

"Smuggling cannabis was a wonderful way of living -- perpetual culture shock absurd amounts of money and the comforting knowledge of getting so many people stoned" he told The Observer newspaper in an interview last year.

"It's impossible to regret any part of my life when I feel happy and I am happy now so I don't have any regrets and have not had any for a very long time."

AFP