Edward Kelsey
From Tardis Wiki, the free Doctor Who reference
Edward Kelsey appeared in several Doctor Who stories: as a Slave buyer in The Romans, Resno in The Power of the Daleks and Edu in The Creature from the Pit.
According to the DVD commentary for "The Slave Traders", the reason for Kelsey's repeated return to Doctor Who was because Christopher Barry — the director of Kelsey's three stories — liked to draw from a stable of reliable actors for his supporting casts. The commentary claims Kelsey is the first non-regular actor to appear with three different incarnations of the Doctor. This is incorrect as Bernard Kay had already appeared with the first three Doctors.
