The reformed lothario has apparently been seeing several women since he ended his marriage to the One That Got Away singer.
If the rumours are to be believed, Katy was told by friends that her ex had already begun to move on.
A source close to the couple told Us Weekly that Katy, 'Discovered through her friends. One of the women told a friend of hers and it got back to Katy.'
If that wasn’t enough reports claim that Russell has been badmouthing Katy.
The source said: 'He's spoken terribly about Katy to them.'
We don't believe that for a second!
The 36-year-old announced that he was ending his marriage to his wife of 14 months at the end of December 2011.
Do you believe the rumours Russell Brand has begun dating again? Let us know in the comment box below...