Time Agent
Time Agent was the designation of individuals who worked for the Time Agency. One of the Doctor's friends, and sometimes companion, Jack Harkness was once a Time Agent.
Captain John Hart was a former partner of Jack Harkness during their time in the Time Agency, both professionally, and sexually. During their time in the Agency, Hart was trapped in a two-week time loop with Jack for a period of five years. While briefly arguing over who the "wife" was in the relationship, Hart agreed that he had been "a good wife, too". (TV: Kiss Kiss, Bang Bang)
As part of his revenge against the Doctor, Adam Mitchell used Cyberman technology to lure Agent Neal Shaw to Henry van Statten's vault, ambushing him and stealing his vortex manipulator. (COMIC: Mystery Date)
Time Agents were forbidden from handing out any form of technology on missions. When Yasmin Khan tried to keep the Tenth Doctor away from the Thirteenth Doctor's TARDIS, she bluffed that she was a Time Agent only for her to casually give him her, causing him to quickly call her bluff. (COMIC: A Little Help from My Friends)