The policemen go to London Victoria station to investigate a left luggage locker there. A library "railway station" shot follows, very obviously of London Paddington station.
Inspector Gregory introduces himself to Howard Rogers as Detective Chief Inspector Gregory. However, later on in the film when he is interviewing the Railway station Luggage Clerk and shows his identification, the clerk responds with 'Superintendent'.
The character of Mrs. Rogers is supposed to be left-handed but uses her right hand instead in several scenes.