Simon Cowell

Simon Cowell replaced by Gary Barlow on Walk The Line judging panel

Cowell said he wanted to "focus on his role as creator and producer" for the debut series of the music game show.

He said he was "thrilled" Barlow would be "picking up the baton" as his replacement, after two decades as an on-screen judge.

The singer said he's looking forward to "discovering new talent" in the role.

The show will offer musical variety acts a chance to win a cash prize but then they must decide if they want to cash out or gamble to stay in the competition.

Simon Cowell breaks back falling from electric bike

The 60-year-old music mogul was taken to hospital for an operation, his spokeswoman said.

"He's doing fine, he's under observation and is in the best possible hands," she said after he was admitted.

Cowell, best known for hit shows The X Factor and Britain's Got Talent, is spending lockdown in the US, where he now lives.

"Simon has broken his back and is having surgery this evening," his spokeswoman confirmed, soon after his arrival at hospital. The surgery began on Saturday evening Los Angeles time.

Gabrielle Union: Ex-America's Got Talent judge discusses 'toxic' environment

The LA's Finest actress left the talent show after one series, with reports saying she had been dismissed.

She has now told Variety she raised concerns with producers but "felt singled out as being difficult".

NBC and AGT's producers said they took her concerns "extremely seriously", and they "had no bearing" on her exit.

Union was on the panel for the 14th series of the hugely successful show, with an option to stay on for another year.