[1] By 1954, Radd had graduated to the West End, where he appeared with Kenneth Williams in two different productions in the Apollo Theatre in February 1956, The Buccaneer and The Boy Friend.

Radd gradually lost interest in theatre and broke into television in Ordeal by Fire in 1957 as a dastardly Frenchman with Peter Wyngarde and Patrick Troughton whom he appeared with in the BBC production of A Tale of Two Cities (1958).

In that year, Radd also appeared in the NBC production of The Tempest playing the role of the drunkard Stefano, alongside Richard Burton who portrayed Caliban and Maurice Evans as Prospero.

To protect his shady Government department ("The Section"), Hunter brings once-top operative and assassin David Callan (Edward Woodward) back to kill Schneider, an international illegal arms dealer.

In the sixth episode of Randall and Hopkirk (Deceased), "Just for the Record" in 1969, he played the role of the villain Pargiter, a deluded character intent on proving he was heir to the throne of England.