Leon's alcoholic father who kicked him out before the start of the series. He phones Leon in episode 3 and Leon says he could be charged with grievous bodily harm. He first appears in episode 4 when he leaves the police station and phones Leon, but Leon does not answer.
He interrupts Leon's training session at the community centre and asks for his money back. Leon does not know what he means but they go back to the flat and Malcolm punches Leon, taking the money Leon and his friends have saved. In episode 5, Leon gets a call to say Malcolm is in hospital. In episode 9, Leon visits him but he has discharged himself, and does not answer his phone.