Marks' 1996 autobiography detailed his many years smuggling cannabis
Tributes have been paid to Howard Marks, the former drugs smuggler known as Mr Nice, who is reported to have died aged 70.
The Guardian reported that the writer died at his home near Bridgend in South Wales.
Marks announced he had inoperable bowel cancer last year.
Friend and former colleague at Loaded magazine James Brown told The Guardian that Marks was a "true modern-day folk hero", who had done "so many funny, shocking, illegal things".
He said: "He stood for everything we loved. Mr Nice was a thrilling book. Howard is a bloody great example to us all."
Marks had a monthly column at Loaded for five years and released his autobiography, Mr Nice, which detailed his many years smuggling cannabis, in 1996.
After years living under as many 43 aliases, he was eventually caught by the American Drug Enforcement Agency in 1988.
He was sentenced to 25 years at one of America's toughest prisons - Terre Haute, Indiana - and was released on parole in 1995 after serving seven years.
After his release from prison he became a prominent campaigner for the legalisation of cannabis and toured a comedy show.
He stood for parliament in four separate constituencies in the 1997 general election on the single issue of the legalisation of cannabis, catalysing the formation of the Legalise Cannabis Alliance.
In an interview with The Observer in January 2015, Marks said he had come to terms with his illness.
He said: "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.
"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."