TORONTO (Reuters) - Comedian Tommy Chong has spent almost three decades wringing laughs from cigar-sized joints and smoke-filled vans but now a nine-month jail term has turned him serious and revitalized his flagging career. Promoting his documentary "a/k/a Tommy Chong" at the Toronto International Film Festival, he hopes the film will expose what he says is the U.S. government's heavy-handed dealing with marijuana offenders in the post-September 11 era. "The United States is under martial law, it's under dictatorship," the 67-year-old father of four said in an interview. The film chronicles the Canadian-born comedian's 2003 arrest and imprisonment for selling drug paraphernalia online to an undercover U.S. drug enforcement agent. The bust was part of a sting operation known as "Operation Pipe Dreams," which the film likens to a witch hunt by former U.S. Attorney General John Ashcroft following claims that drug trafficking financed terrorist activities. The film's producers say the federal government spent $12 million pursuing Chong and compare that to the $25 million bounty for the capture of Osama bin Laden. Chong has been an outspoken marijuana advocate since his days in the Cheech and Chong comedy team, which rode pot culture to fame in the 1970s with films like "Up in Smoke" and "Still Smokin." The documentary suggests the government's motive was not to rid the Internet of a mail-order pipe-and-bong business but to send a message about Chong's three decades of movies and stand-up routines celebrating marijuana use. "DEA AFRAID" "The DEA was afraid that 'Up in Smoke' (the 1978 movie that made Cheech and Chong a household name) was going to be around forever and ever subverting young kids," Chong said. "Now, we've got this documentary that's going to be around forever." Faced with the prospect of seeing his wife and son -- who was running the pipe business -- being prosecuted, Chong said he made a deal to serve nine months in a minimum-security prison. "It was easier for me to go to jail and do the time than it would be to fight," he said. Since his release in 2004, Chong has worked the ordeal into his comedy routines and has been enjoying a larger stage than in his recent past. "Jay Leno is a good example," he said. "He had me on the 'Tonight Show' before but just for little peripheral things, never on the couch, and when this happened, now I've been on the couch twice now." "It's like the weed culture. You just wait, it'll change. Everything changes. Bush won't be in power forever, Ashcroft is already gone. There's going to be another cycle and it's going to go the other way."