Howard Marks, the former drugs smuggler known as Mr Nice, has died, it has been reported.
The 70-year-old 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".
Marks had a monthly column at the magazine 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.
Brown, who hired Marks when he was the editor of Loaded, paid tribute to his friend, saying: "He stood for everything we loved. Mr Nice was a thrilling book.
"Howard is a bloody great example to us all."
Born in 1945 in Kenfig Hill, a small Welsh coal-mining village near Bridgend, Howard Marks went to Oxford University where he earned a degree in nuclear physics and post-graduate qualifications in philosophy.
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 (Norwich South, Norwich North, Neath and Southampton Test) in the 1997 general election on the single issue of the legalisation of cannabis, catalysing the formation of the Legalise Cannabis Alliance.
A 2010 film about his life starred fellow Welshman Rhys Ifans.
He is survived by four children.
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."
Reflecting on his career, he said: "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."