Kagan was supposedly a Starfleet ensign assigned to Internal Affairs. In actuality, Kagan was a hologram within a Section 31 simulation.

As part of the program, he accompanied Luther Sloan to Deep Space 9, during the investigation of Doctor Julian Bashir. Bashir was accused of being a Dominion spy. When Bashir was arrested, Kagan escorted him to a holding cell and was outraged at Bashir. He claimed that he was a member of the Seventh Fleet and had lost many good friends in the battle with the Jem'Hadar in the Tyra system. (DS9: "Inquisition")

Kagan was played by actor Benjamin Brown.
His name comes from the script.
The Star Trek Encyclopedia (4th ed., vol. 1, p. 398) authors believed this character to be real and that he was an operative in Section 31.
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