Actor Sean Penn on his latest movie 'The Gunman'

Two Oscar wins testify to a star who has managed to rise above a troubled past - a criminal record for assault, a rocky marriage to Madonna and emerge as an actor with real kudos.

It was surprising then to find that he had agreed to make a film like The Gunman, his latest blockbuster.

It is a high octane thriller with a twist set partly in the developing world where Western exploitation is rife.

The BBC 's Andrew Marr asks Sean Penn about his very personal involvement in relief efforts in New Orleans and Haiti, and whether his new action film has a political message.