Elements of the plot are based on the mysterious death of barrister Charles Bravo in 1876.
This is the first Paramount picture produced in the UK after World War II.
One of over 700 Paramount productions, filmed between 1929 and 1949, which were sold to MCA/Universal in 1958 for television distribution, and have been owned and controlled by Universal ever since. Its earliest documented telecast took place in Milwaukee Thursday 7 May 1959 on WITI (Channel 6), followed by St. Louis 17 September 1959 on KMOX (Channel 4), by Seattle 12 October 1959 on KIRO (Channel 7), by Boston 13 November 1959 on WBZ (Channel 4), and by Phoenix 27 November 1959 on KVAR (Channel 12). It was released on DVD 15 November 2016 as part of the Universal Vault Series.
"The Screen Guild Theater" broadcast a 30-minute radio adaptation of the movie on January 13, 1949, with Ray Milland reprising his film role.