Michael Douglas pulled his groin at his son's Bar Mitzvah

During an appearance on 'The David Letterman Show', he revealed: "They have this celebration where they take you to put you up in a chair. The guys who are in the back are pushing too hard; the guys couldn't hold me at the front. I went forward and then the old groin went."

The 'Last Vegas' star - who also has daughter Carys with his wife Catherine Zeta-Jones - admits Dylan's Bar Mitzvah was a very proud day for him and the entire Douglas family.

He said: "He had a Bar Mitzvah in May, which was a tremendous success, I'm so proud of him since neither Catherine or I had a formal religious background. He did a great job."

Michael also admitted that he finds it "scary" how, as he ages, he looks more and more like his father, 97-year-old movie legend Kirk Douglas.

Michael said: "It's getting a little scary. My father called about six months ago and he said, 'Son, I saw one of my old movies on television. I couldn't remember it.'

"I said, "Dad, you're getting older.' And he said, 'No, son, it's not that ... I kept looking and I realised, it wasn't me, it was you!' "