The Secret Partner is a 1961 British thriller film directed by Basil Dearden and starring Stewart Granger, Haya Harareet and Bernard Lee.

[5] John Brent is an executive, working under Charles Standish at the London head office of a shipping company.

His marriage is in trouble because he is always short of money; his wife Nicole, certain he is spending it on another woman, leaves him and takes up with Clive Lang, a decorator they have hired.

One day a stranger, his face masked and his voice disguised by an insert in his mouth, arrives at Beldon's home.

Henderson jumps to the conclusion that Brent is guilty and provided the impressions to the actual thief; Hanbury, who is about to retire and wants to leave things neat and tidy, is less certain and insists on a proper investigation.

She feels he took advantage of her by faking the breakup of their marriage and saddling her with Lang's attentions, and now she has fallen in love with another man and wants to leave him for real.

[6] It was shot at the MGM-British Studios at Elstree and on location at a variety of settings across London, including Tower Bridge, the Royal Docks, Greenwich and South Kensington.

[8] In AllMovie, Eleanor Mannikka called the film a "routine mystery story";[9] while in the Radio Times, Allen Eyles noted "an implausible but ingenious British thriller...flashily directed by Basil Dearden...It remains watchable thanks to some skilful characterisation and the strong performances of Stewart Granger as the executive, Norman Bird as the dentist, and Bernard Lee as the dogged, chain-smoking policeman looking forward to retirement.