Actor Tommy Chong has revealed he's partly responsible for the book that inspired MARTIN SCORSESE's new film The Wolf Of Wall Street - because he encouraged writer Jordan Belfort to chronicle his wild life. Belfort was convicted of crimes related to stock market manipulation and served 22 months of his four-year sentence in federal prison in 2004. The Up In Smoke star and Belfort were cellmates and the comedian claims he gave the stockbroker tips on how to write a better book. Belfort's story went on to become a huge hit and now Leonardo DiCaprio is playing him in Scorsese's new movie. Chong tells TMZ.com, "He (Belfort) started writing his book... and he showed me and I kind of insulted him because I told him, 'You haven't written anything,' and he got really mad... So he ended up rewriting it, I told him how to do it. I said, 'Just write from the heart and just write about what you know,' and next thing you know, he's got a bestseller and a movie." But Chong insists he deserves no credit for the success of the book - he is just happy to see Belfort doing well. He continues, "Just seeing him do good (is enough). Actually my biggest thrill is watching him make money, honestly..." The Wolf of Wall Street is due to hit theatres on Christmas Day (25Nov13) in the U.S.