- You may be looking for the John Benton of another universe.
Platoon Under-Leader Benton was a non-commissioned officer of the Republican Security Forces at the Eastchester Scientific Labour Camp carrying out Stahlman's project on the parallel Earth which the Third Doctor visited.
Unlike his counterpart on the regular Earth timeline, Platoon Under-Leader Benton was little more than a cruel and ruthless thug. When coming to assist the Brigade Leader, Benton was caught by the Primord Director Stahlman and the infected technicians, and a handful of Stahlman's ooze was rubbed across his face; he then mutated and became one of the creatures. (TV: Inferno)
His fate, and indeed the fate of all the others who mutated, is not clear. Despite being able to survive the volcanic disaster, he may have been among the Primords killed by the Republican Security Forces when they partially rebuilt Great Britain's infrastructure to support the government's attempts to evacuate to another Earth. (PROSE: The Face of the Enemy)