Gideon Vandaleur

Gideon Vandaleur was an envoy of the Silence. Six months after his death, the Teselecta had assumed his form while investigating the Silence. The Doctor visited the Teselecta-Gantok and asked him for information about the Silence, specifically their weakest link. The Teselecta told him that it was Gantok. (DW: The Wedding of River Song)