triple agent

triple agent (plural triple agents)

1. A spy who pretends to be a double agent for one side, while actually acting as a double agent for the other side.
   • 1980 [1962], Ian Fleming, chapter 11, in The Spy Who Loved Me, →ISBN, page 150:

     There are also triple agents—people who do what the doubles have done, but change their minds and, under our control, pass phoney intelligence back to the Russians. Do you understand? It’s nothing but a complicated game, really.

• double agent