From the Radio Times:

5.50 Colour
Dr Who
starring
Jon Pertwee
The Mutants
A six-part story
by BOB BAKER
and DAVE MARTIN
Part 6
The Marshal is on trial - with the Doctor as chief witness.  But Jo and the Doctor's friends are the Marshal's prisoners.  Will the Doctor dare to reveal the truth about the Marshal's crimes?
Title music by RON GRAINER
and the BBC RADIOPHONIC WORKSHOP
Incidental music by TRISTRAM CARY
Script editor TERRANCE DICKS
Designer JEREMY BEAR
Producer BARRY LETTS
Director CHRISTOPHER BARRY