This file photo shows actor Charlie Sheen being interviewed as he arrives for the taping of the television show "The Comedy Central's Roast of Charlie Sheen" at Sony studios in Culver City, California September 10, 2011. Photo: Mario Anzuoni

Russell Brand and Charlie Sheen have pet names for one another.

The British comedian and the 'Anger Management' star - who underwent a public meltdown last year - have struck up a friendship after working together recently promoting shows on network FX and the US actor came up with some special monikers for them to use.

Russell explained to The Sun newspaper: "I got an answerphone message, 'Brand, Genius One. This is Genius Two'.

"There were instructions to go to his house. There was him being Charlie Sheen - which was out of control - sat with a bunch who looked really on the edge.

"I think he's super-cool and funny as f**k."

It was recently claimed that 'Brand X' presenter Russell - who has previously battled addictions to drugs - has invited Charlie to join his yoga class.

A source said: "Russell and Charlie have been spending an increased amount of time together as they've been named by FX as the stars for their summer schedule so have done a lot of promotional work together.

"Russell has invited Charlie to join him at his yoga classes." - Bang Showbiz