Kelly Clarkson exposes the truth behind American Idol winnings

The truth behind the huge winnings supposedly awarded by reality TV shows like American Idol was revealed by the singing competition's first-ever winner and biggest success, Kelly Clarkson.

The 'Since U Been Gone' singer exposed the reality behind the big numbers advertised by the shows, with Clarkson supposedly winning $1 million for American Idol in 2002. But that million never arrived in her bank account.

She revealed the long-suspected truth on Tuesday's instalment of The Kelly Clarkson Show, where she was joined by Harry Potter star Daniel Radcliffe and another reality TV winner, Daniel Rausch - who just 'won' $220,800 on the fourth season of The Traitors.

When Rausch revealed that he was yet to see a cent of his prize money, Clarkson was unsurprised. “You probably weren’t alive when I was on American Idol,” she said. “I literally was on the show, and they were like, ‘Oh, you win a million dollars’ or whatever. No, you didn’t."

Clarkson said 'they lied' about the supposed $1 million winnings (Weiss Eubanks/NBCUniversal via Getty Images)

She then blasted the dishonest way that contestants were treated, saying to Rausch: "They lied. You did not. It was, like, a million dollars worth of investment in you."

So the '$1 million' was spent on promoting and developing their music career, which is not quite what you'd expect when you're told there is a $1 million prize.

Both her guests were shocked to hear that so many reality shows make a big deal of their huge cash prizes, which rarely materialize as the amount promoted on TV. But it wasn't just money that the former Fox-hosted series had promised her.

“They said you get a car, and I needed it ‘cause my car was bashed in, and I couldn’t afford the deductible," Clarkson shared with her guests. "I did not get a car. And then Clay Aiken, who didn’t win the second season, got a car.”

Remembering the injustices she suffered over 20 years ago when she was barely older than 19, she continued: "I was like, ‘What the f--k?. I remember Clay telling me that the second season, he’s like, ‘Yeah, they gave my mom one.’ I was like, ‘I’m gonna actually kick your ass right now.’"

Kelly Clarkson was the first-ever winner of 'American Idol' (Kevin Winter/ImageDirect/FOX)

Radcliffe, who himself had to navigate the slippery world of showbiz at a young age, told Rausch and Clarkson that early winners of reality TV competitions deserved to have their prizes upgraded if future contestants get a better deal.

He argued: “There should be some system where if you win something on the first season of something, whatever the prize has become, you should retroactively get that,”

But Clarkson pointed out that American Idol hadn't even followed through on the prizes they'd promised at the time, saying: “No, it was supposed to be the prize then, OK? It was supposed to be the prize then!”

With decades to think about the TV show that turned her into one of the most successful female artists of the 21st century, Clarkson turned to Rausch to advise: “That’s why I’m saying — you might not see it.

“But, you know, I hope you got enough TV time.”

American Idol's parent company Disney has been approached for comment.