The 95-year old actor, known for portraying Captain Kirk in sci-fi franchise Star Trek, called out a Facebook group he claims is using AI to create "horrible fake news stories" about him.
"They have created stories that say I have stage 4 brain cancer, was in some kind of fight with Erika Kirk and that I'm dying," he said in a post on X.
"All their stories are monetized. Most of the stories use an AI image of me."
The actor went on to warn of the dangers of AI, and that although it had its benefits, he said it could also be used as a weapon.
"None of these stories are true but they apparently seem genuine enough for fans to repost them across social media and send messages of support to me and my family all while the culprits behind the account make money.
"This is the downside of AI and yellow journalism. While can be a wonderful tool in the right hands; it can be used as a weapon in the wrong hands.
"If you see a bizarre story about me; unless you see it posted on one of my verified accounts take it with a grain of salt."
Shatner starred in the original 1960s Star Trek series as the captain of the Starship Enterprise - a role he reprised in the film adaptations.
The Facebook group appears to have been removed from the platform.
Facebook has been contacted for comment.
