John Ladiver was a criminal and former pilot who was married to Ijayna. He was tall and physically strong. He was arrested for crimes on every planet in the solar system and had broken every law in space. He wanted to escape the prison ship he was on and wanted Harry Sline.
Ladiver was accused of reactivating the Daleks but he worked out that Bob Slater had betrayed them. He was criminalised because of the report that he made after a patrol to Skaro whilst as a pilot. (AUDIO: The Curse of the Daleks)