 "Manhunt" marks the first contributions of voice actor David Healy to the series, here providing the voices of a Spectrum geiger counter operator and one of the Culver Atomic Centre security guards.The mechanic's radio plays the theme music for Gerry Anderson's film "Crossroads to Crime" (1960).The episode's original incidental music was recorded during a four-hour studio session held on 16 April 1967 with a group of 14 instrumentalists.