Charlie Sheen has denied reports that his infidelity was responsible for his marriage breaking up.

Last week, his wife Denise Richards shocked the world by announcing their marriage was over, even while she was six months pregnant with the couple's second child.

'I did not cheat on my wife. These stories and allegations are unconscionable,' Fox News quoted Charlie as saying.

'The reason for our separation is a private matter between the two of us,' the Platoon star added.

Denise walked out of their residence after Charlie was allegedly caught at a party surrounded by prostitutes.