1.   He was arrested after trying to sell guns to an undercover FBI agent.

2.   I want to apply to become an undercover agent.

3.   In the guise of travelling labourers they were sent to Wokingham Fair as undercover agents.

4.   Michael Osborne told investigators that drugs were so prevalent at Cyberzone that undercover agents needed help from fellow deputies working off-duty.

5.   Normally, however, he was resident in London, operating as an undercover agent there.

6.   The Fedpol had undercover agents there, naturally, but no official presence.

7.   The informant showed gun crates Marked with the names of Norinco and Poly Technologies to an undercover agent.

8.   They had undercover agents everywhere in the hotel.

9.   Undercover agents have been tracking him for weeks.

10.   The gang was infiltrated by undercover agents.