secret agent
intelligence officer
intelligence agent
operative

In less than a half hour, two Intelligence agents were on the job.

R-1 was made of the same stuff as other great Intelligence agents.

He wasn't required to be an Intelligence agent all the time.

Until 1979, Western intelligence agents did not even have a current photograph of "the man without a face."

Maybe it was a safe house for intelligence agents who were on the run?

At some time in his life he must have been an experienced intelligence agent.

He's the biggest Intelligence agent we've brought in so far.

G-8 nodded to the Intelligence agent who had brought the information to him.

A military operation left too many sources open to foreign intelligence agents.

Any intelligence agent, already within the service, however, knows certain secrets.