Thug 3 (City of Death)

A thug worked for Count and Countess Scarlioni in Paris in 1979. After Hermann executed his two predecessors for failure, he and a partner went and brought the Fourth Doctor, Romana II and Detective Duggan to the Scarlionis' chateau. He and the fourth thug were present during the Count's pre-heist planning of the theft of the Mona Lisa, and the two presumably went with Hermann to the Louvre to steal it. After the Doctor returned from 1505 and came to confront Scaroth at the chateau, this thug captured him and brought him in at gunpoint. The Doctor commented on his quiet nature and said the thug reminded him of William Shakespeare in that regard. (TV: City of Death)

Behind the scenes
Anthony Powell wasn't credited for his appearance in City of Death, but was identified by a call sheet identifying him as "Thug #3".