Special Branch. S04 E07. Sounds Sinister.

First broadcast 28th March 1974.

It's blackmail with a difference. Key public figures are having dirty linen washed in public by a pirate radio station.

George Sewell ... Detective Chief Inspector Alan Craven
Patrick Mower ... Detective Chief Inspector Tom Haggerty
Paul Eddington ... Strand
John Carson ... Phillip Weston
Stanley Meadows ... Max Levinson
Claire Nielson ... Det. Sgt. Isobel Ross
Peter John ... Pugh
Heather Page ... Anna Maslyn
Peter Cleall ... Stuart Barnes
Antony Webb ... Irving Shannon
Wendy Seely ... Maggie
John Clive ... Whacker
Valerie Leon ... Juanita Wayne
Richard Pescud ... Communications Expert
Bruce Bould ... Technician
Heather Barbour ... Girl at Party
Vi Delmar ... Lady in Pub (as Vi Delma)