Secret People stars Valentina Cortese, Serge Reggiani and Audrey Hepburn and premiered in the U.K. on 8 February 1952.

In 1930, Maria Brentano and her younger sister Nora flee to London as their father is about to be executed by his country's dictator.

After having appeared in a string of bit parts and small speaking roles, the film provided Audrey Hepburn with her first significant film role, leading to her big breakthrough in Roman Holiday: on 18 September 1951, shortly after Secret People was finished but before its premiere, Thorold Dickinson made a screen test with the young starlet and sent it to director William Wyler, who was in Rome preparing Roman Holiday.

Wyler wrote a glowing note of thanks to Dickinson, saying that "as a result of the test, a number of the producers at Paramount have expressed interest in casting her.

He also praised "a sensitive performance by Valentina Cortesa, ...a substantial role for Audrey Hepburn", and felt that the film had been misinterpreted and "was in some respects ahead of its time.