I haven't heard that but must admit I thought he was very strange. He wrote a book, 'My bookywook', or something like that, some years ago. I've never read it but it may give insight to his personality.
Found this: "My Booky Wook is Russell Brand's scandalous, hilarious, and raw memoir chronicling his chaotic journey from a troubled Essex childhood through severe addictions (sex, drugs, alcohol) and disastrous stints in school and entertainment, culminating in a story of struggle, redemption, and his unique, chaotic rise to fame, blending vulgarity with surprising literary flair and intelligence."
I saw him acting in a TV drama and he was very good, quite convincing in the role (in which he played a rather odd, creepy character :)).
Brand's conversation was always rather lewd but I thought that was a pose, never dreamed he sexually assaulted anyone until all this came out.
Horrible!