George Clooney wrote "fake notes" to his fellow actors, in which he pretended to be Bill Clinton.

The 61-year-old actor - who is known for his love of pranks - was mocked by his friend Matt Damon in a speech at the 45th Annual Kennedy Center Honors, who told the audience he used to impersonate the former president to fool his pals, and also recalled an infamous gag where the 'Up in the Air' star "defected" in his former flatmate's cat litter tray.

In a preview clip for the event - which will air on TV on 28 December - obtained by E! News, Matt said: "It has been said that my friend George Clooney is the last of the true movie stars.

"So I got to thinking about exactly what that meant. Of course, a number of past Kennedy Center honourees have certainly been movie stars in that classic sense.

"Actors with class and sophistication — Cary Grant, Henry Fonda, Paul Newman, Gregory Peck.

"And then I think of George. A man who defected in Richard Kind's kitty litter box as a joke.

"A man who once stole Bill Clinton's stationery and wrote fake notes to actors, saying how much the President loved their movies."

George spoke about his prank on Richard on the 'SmartLess' podcast last year, explaining how his friend's cat hadn't "taken a s*** in three days".

He continued: "He takes the cat to the vet, and they give him this kitty Metamucil. And so now this little kitty is s******* 15 times a day, and I am scooping it all up, because I have nothing else to do. I have no idea why. It's just funny."

The 'Ticket To Paradise' star then had a revelation about what he "must do" to prank his pal.

He continued: "And then after a couple of weeks, the light bulb goes off, and I realise what I must do. I must take a s*** in the cat box.

"Now there is this moment, when I'm squatted down over a cat box where I'm going, 'Really? I mean, it's funny. It's good. But I'm not sure it's how I want to be remembered…' The cat is like six-inches long. It's a tiny cat."

Richard eventually figured out what had happened but failed to see the funny side.

George said: "He gets madder and madder and madder.

"And then finally he says, 'I understand humour! Defecation doesn't make me laugh!'"