Controversial Alberta anti-oilpatch activist and convicted bomber Wiebo Ludwig says he is battling cancer.

"I have cancer of the esophagus. It could be terminal," Ludwig told CBC News.

Ludwig, 69, received the diagnosis a few months ago and says he will learn next week how serious his condition is. He has only been receiving natural injections so far and says he isn't interested in undergoing chemotherapy or radiation treatment.

"Generally, they just extend your life a bit on all of those," he said. "And if that's all they're doing, I would just as soon sign off earlier."

Ludwig has long been a controversial figure in the Alberta oilpatch.

No one has ever been charged in the 1999 fatal shooting of teenager Karman Willis on his Trickle Creek farm.

In 2000, Ludwig was found guilty on five charges related to bombings and vandalism of oil and gas wells in northwestern Alberta. He served two-thirds of a 28-month prison sentence before he was released in 2001.

In January 2010, hundreds of RCMP officers searched his property looking for evidence related to six EnCana gas pipeline bombings. RCMP said they found his DNA on the envelope of a threatening letter sent to a local newspaper.

Ludwig was arrested and released after spending one night in jail. He was never charged.

Ludwig was in Edmonton Friday for a weekend screening of Wiebo's War, a new National Film Board documentary about his life. He said he hopes he lives long enough to write a book about his fight.

"And probably publish it posthumously so they don't put me in jail," he said.