Arthur Lisser / ... (2 episodes, 2002-2006)
Supt. Wilf Penfield (5 episodes, 1985)
Quartus (unknown episodes)
Chief Inspector Parker (4 episodes, 1973)
Det. Inspector Parker (5 episodes, 1972)
Detective Inspector Parker
Lawrence Webb / ... (5 episodes, 1972-1983)
Lt. Cmdr. Donald Kimberly
Marco Polo 7 episodes, 1964
Bill Mercer / ... (3 episodes, 1963-1969)
Jacques Beronne / ... 2 episodes, 1961-1962
Alan Bradley / ... (28 episodes, 1981-1989)
Oliver Marchant / ... (2 episodes, 1963-1965)