George Clooney hasn't forgiven Russell Crowe for calling him a ''sell out''.

The 'Gravity' star fell out with the 'Gladiator' actor in 2005, after he slated him in an interview with GQ magazine.

The silver-haired actor was slammed by Russell, 49, for modelling suits in an advertising campaign, and then shortly afterwards George was sent a poetry book by way of apology - something he didn't accept.

The 52-year-old actor told the new issue of Esquire magazine: ''The truth is that [Russell Crowe] did send me a book of poems to apologise for insulting the s**t out of me, which he did.

''And that's when he really went off on me. 'Who the f*** does this guy think he is? He's a Frank Sinatra wannabe.' He really went after me.''

Knowing that he might run into George during awards season later on, Russell then attempted to apologise for his actions.

George said: ''I think he said, 'I was misquoted,' and I was like, 'Yeah, yeah. Whatever.' ''

George also spoke candidly about Leonardo Dicaprio and how the pair played a basketball game together after striking up a friendship.

Leo's over-bearing friends talked a good game before the match, but George's team ran out easy winners - leading him to contemplate whether Leonardo, 39, has enough honesty in his life.

George said: ''The discrepancy between their game and how they talked about their game made me think of how important it is to have someone in your life to tell you what's what. I'm not sure if Leo has someone like that.''