Although the vendor states that there were two trenchcoats used in the film, the whereabouts of the other one is unknown.

Michael Caine's black trenchcoat is a key costume featuring throughout the film. It is first seen over Caine's arm as Carter leaves the train on reaching Newcastle. Carter then wears it throughout the film whenever an overcoat is used, even in the final sequence when he's assassinated on the shore.

Johnny Morris was stunt director and technical advisor on this film. He was particularly keen that the fight sequences should be realistic. Unlike other action films of the period, such as Bond, where the fights went on for 5 minutes or more, he wanted them to be as close to authentic gangster fights as possible. In his words: "When someone got hit...they stayed hit. He persuaded director Michael Klinger and Michael Caine of the merits of this method and as a result the impact of these sequences was brutally shocking.