In the field of counterintelligence, a double agent is an employee of a secret intelligence service for one country, whose primary purpose is to spy on a target organization of another country, but who is now spying on their own country's organization for the target organization.
[1] Double agentry may be practiced by spies of the target organization who infiltrate the controlling organization or may result from the turning (switching sides) of previously loyal agents of the controlling organization by the target.
They are often very trusted by the controlling organization since the target organization will give them true, but useless or even counterproductive, information to pass along.
[2] Red Orchestra Gestapo Nazi Germany Soviet Union South African citizen South African citizen South African citizen A re-doubled agent is an agent who gets caught as a double agent and is forced to mislead the foreign intelligence service.
Begoum describes the re-doubled agent as "one whose duplicity in doubling for another service has been detected by his original sponsor and who has been persuaded to reverse his affections again".