By Mark Savage
BBC News entertainment reporter
Cowell said the leaked document was a standard employment contract
Simon Cowell says he is "very embarrassed" that the contracts signed by this year's X Factor contestants were leaked to the Mirror newspaper.
The 80-page document, which is enforceable "anywhere in the world or the solar system" was signed by all 12 finalists before the live shows began.
It includes a clause that prevents them from saying anything "unduly negative, critical or derogatory" about Cowell.
"I didn't put that in there," the music mogul said. "Very embarrassing."
"I wasn't aware that one of the clauses said you can't be horrible about me," he added.
"It's probably the most useless clause in the history of contracts, because everybody does talk horrible about me.
"And do you know what? I don't care. It sounds ridiculously hypocritical of me to slate most people who come on the show and then to go: 'And, by the way, you've got to be nice about Simon'."
HOW COWELL SAYS THE £1m PRIZE BREAKS DOWN
Prize money: £150,000
Recording costs: Up to £500,000
Music videos: £200,000
He also addressed the issue of how much money the winner receives.
On air, the prize is billed as a "£1m recording contract", but the contestants' contract said the prize money was £150,000.
Cowell acknowledged that this latter figure was correct, but said the total amount of money spent on the winning act exceeded £1m.
"We make over a million pound commitment to the winner. That's why it's described as a £1m recording contract," he added.
The 49-year-old was speaking at a press conference ahead of Saturday night's final - along with the contestants and his fellow judges Cheryl Cole, Dannii Minogue and Louis Walsh.
Minogue declined to answer a question about whether she would return to the series next year - deferring to Cowell, whose production company makes the show.
"Do you know what, we're going to sit down with everybody in January," he said.
"But I would be surprised if it's a different line-up. Although Louis [Walsh] is going to have to get some work done."
The Irish judge retorted: "Is that part of the contract, Simon?
"Well, I want to do the gig, so I'll do it."