Peter O'Toole was originally considered for the part of Charles Norgate, which eventually went to Aldo Ray, but insisted on being cast as Monty Fitch, because he didn't want to be typecast as the Irish boyo.
According to a contemporary article in the New York Times, when director David Lean saw this movie at its London premier, he was greatly impressed by the performance of a completely unknown actor, Peter O'Toole, in the supporting role of Capt. Monty Fitch. He called O'Toole and asked him to do a screen-test for the lead in the title role of his epic classic, Lawrence d'Arabie (1962), but only after Marlon Brando and Albert Finney either refused or lost the part.
The cast included Peter O'Toole, known primarily as a stage actor in London, then heavily in demand after his stage success on The Long and the Short and the Tall. O'Toole later said when offered the role "it wasn't the part I was offered that interested me but the Guards Officer who is reluctantly forced to think."
The London County Council refused permission to film in the city's sewers, so these were reconstructed on the studio's lot. The Bank declined to give permission to film its vaults for security reasons. The sets were based on sketches and old prints from the British Museum of the vaults as they looked in 1900.
This film failed at the box office, resulting in a loss to MGM of $57,000 (about $597,000 in 2023) according to studio records.