Police have dealt with scores of cases involving home-made 3D printed guns in the UK in the last three years. Data obtained by File on 4 Investigates from the National Crime Agency shows that criminals and extremists have attempted to manufacture the weapons.

We hear from police who successfully prosecuted a group who had manufactured printed firearms to sell on to criminal gangs. As Adrian Goldberg asks, how much of a threat are these printed weapons in the UK and what can be done to deter people from making them?

Producer: Paul Grant