The Chairman (1969)

Director: J. Lee Thompson
Cast: Alan Dobie, Anne Heywood, Arthur Hill, Conrad Yama, Gregory Peck, Keye Luke, Ori Levy, Zienia Merton

Synopsis:

An American scientist is sent to Red China to steal the formula for a newly developed agricultural enzyme. What he is not told by his bosses is that a micro-sized bomb has been planted in his brain so that should the mission ever look likely to fail, he can be eliminated at the push of a button!