A tie-in song "The Fool Killer" was written by Burt Bacharach and Hal David and recorded by Gene Pitney but not used on the soundtrack.
First credited film of Edward Albert, son of Eddie Albert. He had an uncredited role in Flucht der weißen Hengste (1963).
Filmed in 1963.
Despite being submitted by distributors Warner-Pathé for BBFC certification in 1966 and being passed with an 'X' certificate, the film does not appear to have received a UK release.