The BBC film sees Elba meet prime minister Sir Keir Starmer, who said that his party would commit to halving knife crime if elected, and the King, where the pair discussed solutions to the problem with some of the young people most affected by youth violence.

In the documentary, called Idris Elba: Our Knife Crime Crisis, the Hollywood star meets a 17-year-old boy at Feltham young offender institution who first began carrying a blade when he was 13. He grew up in a violent home and had been badly bullied at school for having dandruff.

Luther star speaks ahead of the release of BBC documentary in which actor talks to victims’ families, police officers and teenage offenders