Aske

Aske was a friend of Repple who attended a party hosted by Sir George Harding. After meeting up with the Doctor and Rose Tyler, he and Repple offered for them to come and stay at the Imperial Club.

One night, Aske wanted to tell them something important. He and his friend were apparently not who they assume. Aske explained that he was a doctor and was looking after Repple who had lost his memory during a play when they were children. He said that everything about Dastaria was all fake, because Repple was slightly out of his mind.

When Melissa Heart's mechanical robots arrived and he was trapped with Repple and the Doctor inside a hidden control room, he tried to protect Repple's identity by saying that he was not a jailer. He was killed by Melissa Heart using a laser shot from her staff.

Aske turned out not to be a jailer, but a decoy for the real Shade Vassily and his jailer. (NSA:  The Clockwise Man)