Kick-Ass 2 star Jim Carrey has refused to take part in publicity for the film because he believes it is too violent in the aftermath of the Sandy Hook massacre.

The Hollywood superstar, a vocal advocate of stricter gun controls in America, took to Twitter to voice his objections to the movie, in which he plays Colonel Stars and Stripes, a former mobster turned superhero.

"I did Kickass a month b4 Sandy Hook and now in all good conscience I cannot support that level of violence," he wrote.

"My apologies to others involved with the film. I am not ashamed of it but recent events have caused a change in my heart."

Twenty pupils and six staff were killed at Sandy Hook Elementary School in Connecticut last December by 20-year-old gunman Adam Lanza.

Kick-Ass 2 will see the Hit Girl character return
Mark Millar, the creator of the comic book upon which the film is based, asked Carrey to reconsider his decision.

"I'm baffled by this sudden announcement as nothing seen in this picture wasn't in the screenplay 18 months ago," he said.

"Yes, the body count is very high, but a movie called Kick-Ass 2 really has to do what it says on the tin.

"A sequel to the picture that gave us Hit-Girl was always going to have some blood on the floor and this should have been no shock to a guy who enjoyed the first movie so much...

"Like Jim, I'm horrified by real-life violence (even though I'm Scottish), but Kick-Ass 2 isn't a documentary. No actors were harmed in the making of this production!"

Kick-Ass 2, the sequel to 2010's Kick-Ass, follows two children who style themselves as the superheroes Hit Girl and Kick-Ass.

It will be released in the UK on August 16.