During a January (07Jan13) appearance on U.S. programme The Tonight Show with Jay Leno, staunch Democrat Maher offered to donate $5 million to a charity of Republican Trump's choice if he could prove his father wasn't an orangutan.
He said, "The colour of his hair and the colour of an orange orangutan is (sic) the only two things in nature of the same colour."
Unimpressed by the joke, The Apprentice star accepted the challenge and promptly mailed Maher a copy of his official birth certificate, and now he wants the funnyman to pay up.
Trump filed legal papers in Los Angeles on Monday (04Feb13), and Maher has responded to the suit via Twitter.com, writing, "What?? Really? Hahahahahahahahahahahahahahahahahahahahahahahahahaha."
The joke was a play on Trump's relentless efforts to uncover facts about U.S. President Barack Obama's heritage. Last year (12) he promised to give $5 million to the politician's favourite organisation if he released his passport records and proved beyond doubt he's an American citizen.