The Marvel star – who played Silas in the 2006 film adaptation of Dan Brown’s famous novel – opened up about the amusing incident during a recent appearance onThe Late Late Show.
Explaining what happened, Bettany said: “I had to grab him and I had to punch him in the stomach and it’s very quiet on set. It’s always more quiet when there’s a stunt going on because you’re worried somebody’s gonna get hurt.
“So everybody’s listening and I punched him in the stomach and he farted really, really, really loudly.”
The 49-year-old joked that he did not know how to react in the situation, stating: “I didn’t know what the form was. What do you do when the biggest movie star in the world farts?
“I kinda looked at him. And he went, ‘What is wrong with you? You just made me fart!’”
He joked that he “never reached those heights again” in his career.
Hanks told the same story during a past appearance onThe Graham Norton Show.