Russell Crowe has described circumcision as "barbaric and stupid" in a venom-filled online debate on the subject.
The Australian Oscar-winning actor, known for courting controversy in media interviews, wrote on his Twitter page that it was immoral to circumcise male infants and said he would "take attentive parenting over barbarism".
Mr Crowe, 47, added: "Who are you to correct nature? Is it real that GOD requires a donation of foreskin? Babies are perfect."
The father-of-two was responding to a question on the subject from one of his Twitter followers. At one point, he called a man who suggested circumcision had scientific reasons a "moron". Another argued it might be hygienic, prompting the Gladiator star to respond: "Hygienic? Why don't you sew up your a** then?"
Challenged by a follower who suggested he was "comparing sexual mutilation with a Jewish ceremonial act", Mr Crowe said: "Can you actually read the words you just typed "a ceremonial act"? F**K that. The Mayans had ceremonial acts too.'
"Many Jewish friends, I love my Jewish friends, I love the apples and the honey and the funny little hats but stop cutting your babies." He directed the Tweet at the Jewish film director Eli Roth.
Mr Crowe added: "I will always stand for the perfection of babies, I will always believe in God, not man's interpretation of what God requires," before telling his Twitter fanbase that if they felt it was right to "cut things off" their babies, they should "f**k off."
After his comments were reported around the world, Mr Crowe said: "I have a deep and abiding love for all people of all nationalities, I'm very sorry that I have said things on here that have caused distress."
His outburst comes in the week after an American comic book drew accusations of antisemitism for featuring characters called Monster Mohel taking pleasure in circumcision.