The plot is similar to the American film noir by Richard Fleischer, Armored Car Robbery (1950), not only for the plot of crooks robbing an armored car, but the sexy wife of the passive, secondary gang member having a secret affair with the gang leader.
One of many British crime films where Tom Bell plays a criminal underling who argues with his criminal boss. Another is A Prize of Arms. In real life he was a true firebrand and very unpredictable, at one point famously heckling Prince Philip, yelling out "Tell us a joke" to the chagrin of his fellow actor-friends at the table.
In a recent late night U.K. TV broadcast (29/05/18) there is a sequence where a woman is washing her daughter in the bath. The daughter is standing up but from her shoulders down her body was optically blurred while her mother is washing her.
The Pearsons' house is 44 Parkside Crescent, Tynemouth, North Shields - since extended to almost twice its size at time of filming.
The location of the boatyard (Brensham, Norfolk) is fictitious.