Charlie Sheen "never realised how f***ed up" he was until his Comedy Roast this weekend.

A cast of comedians and stars - including guitarist Slash, boxer Mike Tyson and Charlie's ex-wife Brooke Mueller - gathered for the event, which saw comics make fun of the last year of the actor's life, which has seen him struggle with drug addiction, fired from sitcom 'Two and a Half Men' and have a polyamorous relationship with an ex-porn star and a marijuana magazine model.

Sheen sat on stage on a huge throne, surrounded by prop missiles, and was introduced by the night's host, 'Family Guy' creator Seth McFarlane.

He said: "You've seen him on TV. You've seen him in movies. And if you are a prostitute, you have seen him point a gun at your head."

He also referred to an incident at Christmas 2009, when Charlie allegedly threatened Brooke with a knife, saying: "She's here voluntarily, no one put a knife to her throat."

'Private Practice' Kate Walsh joined in, saying: "Charlie is an amazing medical specimen. I guess that's what comes from waking up at the crack of crack."

Jon Lovitz later quipped: "How much blow can Charlie Sheen do? Enough to kill two and a half men."

Amy Schumer also made fun of the star by referencing his replacement on the TV show, Ashton Kutcher - who is married to Bruce Willis' ex-wife, Demi Moore.

She said: "Just like Bruce Willis, you were big in the 80s and now your old slot is being filled by Ashton Kutcher."

At the end of the evening, held at Sony Studios in Culver City, California, Charlie - who had taken everything in good humour throughout the night - remained unrepentant of his lifestyle choices.

He said: "Wow, what a night. Until tonight, I never realised how f***ed up I was. All this time I thought I was just having fun. The thing is once again, I come out unscathed. You can't hurt me. Hell, I can't even hurt me. Drugs couldn't kill me. Sex couldn't kill me. The press couldn't kill me. 'Two and a Half Men' couldn't kill me. Did you really think your little jokes were going to kill me? I'm done with the winning cause I've already won. This roast may be over, but I'm Charlie Sheen.

"In here burns an internal fire. I just have to remember to keep it away from a crack pipe."