informer

The dreaded Stasi, the German secret police, had agents and informers everywhere.

She was recruited as a police informer after being charged with drug offences in 1993.

In Mali, the mercenaries’ uncoordinated, brutal raids on civilian settlements “created chaos and fear within the Malian military hierarchy,” deterring informers from collaborating and creating recruitment opportunities for jihadists, the Sentry’s report said.

There is something about a healthy personality that feels repelled by a snoop, a snitch, a stool pigeon, an informer.

"I think that's probably the only way it's going to be solved - someone on the inside becomes an informer."