Henry Cass Director Tom Conway Tom 'Duke' Martin Actor Honor Blackman Paula Grant , Paula Jackson Actor Michael Balfour Barney Actor Bruce Seton Webb Actor Brian Worth Johnny Matlock Actor Freddie Mills Pat Actor Alexander Gauge MacAllister Actor Lee Horsley Michael Matlock Actor Paddy Webster Diane Grant Actor John Colicos First Kidnapper Actor Larry Taylor Second Kidnapper Actor Arthur Lowe Mitchell Actor Frederick Schrecker Professor Dohlmann Actor Robert S Baker Producer Monty Berman Producer, Cinematographer Norman Hudis Writer Stanley Black Music Ivor Stanley Music Anne Baker Film Editor