Leonardo DiCaprio helping Kate Winslet handle marriage collapse – was there another woman?

[HMG] – We brought you news of the end of Kate Winslet’s marriage to Sam Mendes on Monday, and now the backstory is starting to emerge. And it apparently concerns a young actress named Rebecca Hall.

Sam and Rebecca, 27, had been working together on theater projects in New York and London, and Kate, 34, is said to have grown tired of the rather close friendship that had developed between them.

“When Kate found out Sam had grown close to Rebecca she was upset.” says one of Kate’s friends. “Rebecca is totally Sam’s type  -  a thespian mix of brains and beauty.”

She’s also younger and single. And that’s even worse.

The daughter of one of Britain’s finest theater directors, Sir Peter Hall, Rebecca split from her last boyfriend six years ago and has since focused on her career. She played Vicky in Woody Allen’s 2000 drama, ‘Vicky Cristina Barcelona,’ opposite Scarlett Johansson, and also had a main role in last year’s Ron Howard biopic, ‘Frost/Nixon.’

She and Sam first met in 2006 when Sam was producing the movie, ‘Starter for 10′ in which Rebecca was cast. They also worked in theater last Summer, and were seen together at numerous parties to promote their two plays.

“Sam and Rebecca are good friends,” a friend of Sam’s told the Mail. “But to insinuate there is anything further is taking it too far.’

The marriage began to dissolve in 2008, when Sam directed his wife and Leonardo DiCaprio in ‘Revolutionary Road’ — which oddly concerns a crumbling marriage. Since then her friends say it’s been mostly downhill.

Ironically it was Rebecca who introduced Kate to Sam when Kate left her last husband, James Threapleton — another director — in 2001.

Kate is described as ‘severely on edge’ from the stress of the breakup, but her friend Leonardo is helping her to cope;

“Leo and Kate have been like brother and sister since Titanic. And since Kate’s problems started they’ve got closer again. Kate feels she can tell Leo anything. He’s been a rock for her.” a close source tells reporters.

The former couple, who are known to have been living apart for some time seem determined to keep it that way – Kate is now on vacation in Mexico with her two children, while Sam is working on plays in New York.

And spies say Rebecca is not far away…