Former X-Factor judge Louis Walsh has been rehired by Simon Cowell as a judge on TV talent show, The X Factor.

The pair were spotted at this week�s horse races at Ascot, Berkshire where they discussions about Walsh�s rehiring took place.

"It wasn't until Simon returned from filming American Idol that he realised how popular Louis was� said a source �When Louis turned up on Simon's This Is Your Life they buried the hatchet�.

"Simon told him, 'We've made a mistake, we need you back on the show.' But by that time they'd hired Dannii Minogue and Brian Friedman."

The new series of X-Factor starts in August 2007.