Published Sunday, 23 September 2012
In the N-Dubz star's new memoirs, Honest: My Story So Far, she reveals she was drugged and passed out after a night out to find a man having sex with her.
She writes: "When I came round again, I was in a bedroom and my so-called friend was on top of me, having sex with me.
"I couldn't even move, let alone get up or speak, and once again I just blacked out."
The morning after she was even handed a drink by the boy's mother, who believed she was his girlfriend.
The X Factor judge reveals: "I went into the bathroom and burst into tears. Then I pulled myself together, got dressed, and left without saying another word, crying all the way home."
The singer decided not to tell her parents or the police, but admits she now regrets not fighting for justice.
She adds: "I realise now, of course, that I'd done nothing to be ashamed of and the boy in question should have been prosecuted, but I was young and confused and not strong enough to speak up."