Cirrus@Austlit

The following information is derived form material held in the Crawford Collection:

Michele Fawdon (Mia Sinclair); James Condon (John Black); Pat Leehy (Jeanne Haywood); Anne Charlston (Samantha); Walter Pym (Professor Melton); Malcolm Steed (Dr Eric McLeod); Trevor Woods (Dr Jim Innes); Gary Gray (Robert Elliot); Paul Glen (Hal); Denise Morgan (Salesgirl); Stephen Barker, Joseph Owen, Charles Gilroy, Judy Bierworth, Dido Paton, Edna Bartlett, Beverely Foster, Roger Chevalier, Barbar Mann, and Herbert Payne (Satanists); Karinda Davies (Stand-in: Mia); Brenda Abbey (Stand-in: Julie); and John Kelly (Extra in Ambulance).

The casting call sheets held in the Crawford Collection also show the following information:

Other actors considered for the role of John Black included Arthur Dignam.
Other actors considered for the role of Jeanne Haywood included Beatrice Watts and Kris McQuade.
Other actors considered for the role of Professor Melton included Dennis Pryor, Campbell Copelin, Michael Duffield, John Nash, and Arthur Rudkin.
Other actors considered for the role of Dr Eric McLeod included Alan Hopgood and David Clendenning.
Other actors considered for the role of Robert Elliot included Rod Anderson and Graeme Blundell.
The stuntmen was Graham Mathrick and Tony Sprague: the former has 'nothing dangerous' written next to his casting call, while the latter is slated to jump through a window while on fire.