Celebrity chef Jamie Oliver and his wife Jools are expecting their fourth child in September, their rep confirms to the Press Association.

Oliver, best known in the U.S. for his 'Naked Chef' TV show, couldn't contain his excitement and messaged his Twitter fans: "Guess what.....I'm going to be a dad again!!! We're expecting, so happy, feel very lucky."

The latest addition will join big sisters Poppy Honey, 8 this month, Daisy Boo, 6 1/2, and Petal Blossom Rainbow, 11 months. The Olivers wed in June 2000.