British writer, a former journalist who became active as a theatrical producer. With his wife
Muriel Box, he produced more than 100 one-act plays. Founded Verity Films in 1940, turning out more than 120 shorts for the war effort in the space of two years. Collaborated with his wife Muriel on several feature films, of which the biggest hit was
The Seventh Veil (1945), which won an Academy Award for Best Screenplay. After a spell at Rank, Sydney became head of production at Pinewood in 1949. Retired from films in 1959 to work as a television executive.