Simon Cowell has hit out at Lady GaGa for being the "most boring singer in the world".

The music mogul believes the 'Born This Way' hitmaker, Beyonce Knowles and Katy Perry - who recently matched Michael Jackson's record of having five number one hit singles from the same album on the US Billboard Hot 100 chart - need to be on TV to shine because without a visual medium they are dull.

He told the Daily Mirror newspaper: "If you only ever heard Lady Gaga, she's the most boring singer in the world. You've got to see her - you need TV.

"Same with Beyonce. Or Katy Perry. We're all about image. You have to have that x factor."

Simon, 51, also poked fun at 'American Idol' host Ryan Seacrest, describing him as the "complete opposite" to "intelligent" US 'X Factor' presenter Steve Jones.

He added: "He's tall, dark, British - he's basically completely the opposite of Ryan Seacrest. You've got to add in intelligent as well."

Simon quit his role as a judge on 'American Idol' to launch the new version of his pop star search show.