Alleged affair suggested as reason for couple's divorce

Reese Witherspoon split from husband Ryan Phillippe because he allegedly cheated on her.

A spokesman for the Oscar-winning actress announced the couple’s mutually agreed separation on Monday, but claims have emerged that Ryan had an affair with 24-year-old Australian actress Abbie Cornish.

Ryan, 32, met Abbie on the Texas set of their independent film Stop Loss and it has been reported the couple were extremely open about their relationship during filming.

A source told US Weekly magazine: ‘Ryan did not go out of his way to hide the fact that he was having a fling with his co-star Abbie Cornish.

‘Besides the fact they were spotted making out in a sushi restaurant together, she was spotted many times leaving his loft apartment.’

A representative for Abbie has denied the allegations and representatives for both Reese and Ryan refused to comment.

Reese, 30, and Ryan have two children together – seven-year-old daughter Ava and three-year-old son Deacon.