Whodunnit? was a Thames Television panel game show where 3 celebrities had to solve a murder mystery. The show ran from 1972 - 78 and was hosted first by Edward Woodward, and then Jon Pertwee.
A 15-minute act was performed in the studio in which a murder was committed. The panel then had to question the surviving players and deduce - Whodunnit. William Franklyn provided the voiceover, and typical guests included the likes of Michael Aspel, Liza Goddard, etc. and remember - 'only the murderer can lie'.