'Kick-Ass 3' will be the final installment in the series.

The story of Dave Lizewski and his titular high school hero alter ego - who is played by Aaron Taylor-Johnson - will draw to a definite end after the third film - and writer Mark Millar has admitted it may not come to a happy conclusion.

He told SFX magazine: ''Kick-Ass 3 is going to be the last one. I told Universal this and they asked me, 'What does that mean?' I said, 'It means that this is where it all ends'.

''They said, 'Do they all die at the end?' I said, 'Maybe' - because this is a realistic superhero story.''

Mark believes it is important that the franchise - which also stars Chloe Grace Moretz and Jim Carrey - remains ''realistic'' because the titular character isn't immortal and doesn't have any of the protection awarded to other superheroes.

He added: ''If someone doesn't have a bullet proof vest like Superman and doesn't have Batman's millions then eventually he is going to turn round the wrong corner and get his head kicked in or get shot in the face.

''So Kick-Ass needs to reflect that. There has to be something dramatic at the end, he cannot do this for the rest of his life.''

'Kick-Ass 2' is scheduled for release on June 28 in the US and July 19 in the UK.