The musician and comedian heavily criticises religion in 'The Pope Song', which highlights the issue of child abuse in the Catholic Church.
He says his manager got a letter from someone he describes as a 'mad Catholic', threatening to sue him on behalf of the Church.
Speaking to the Telegraph, he said: "There's a kind of mad Catholic guy who's trying to sue me because of 'The Pope Song'."
"This guy sent a letter to my manager, saying he was trying to sue me on behalf of the Church or something. I just sort of ignored it. I don't believe I say anything that could get me in trouble with the law."
The song about the pontiff begins with a number of swear words and accuses anyone who defends him of being on a moral level with child abusers.