The Girls Aloud beauty became embroiled in a heated argument with her Dutch partner, Theo De Vries, during a ski trip to Austria over the holidays, which ended in her flying home several days early.
Harding was admitted to hospital in the early hours of New Year's Day (01Jan12) and spotted with a bandaged wrist on her return.
However, De Vries, who met Harding while they were both being treated at a rehab centre, vehemently denied he had been violent towards the star.
The singer has now opened up about the incident, revealing the feud was sparked by a discussion about her former fiance Tom Crane, who she split from last year (10).
She tells The Sun, "I think he knew I missed Tom, because I do - desperately. I think in a way I was on a rebound. I think that p**sed him off. I called him Tom a few times by mistake. He hated that. Probably when we were rowing - probably because I used to shout at Tom...
"I have spoken to Tom... We still have a lot of love for each other, but we know we are just not right for each other at this point in time. I think that's what p**sed Theo off. He knew that I still had a lot of love for Tom."
De Vries maintains he didn't hurt the star, saying, "I've never hit anyone in my life. I did restrain her but nothing more."