Star Trek: The Cantabrian Expeditions Wiki

Mikali Galea was a trader and Federation citizen in the late 24th century. He was of Earth's Maltese descent.

Galea fell in love with USS Cantabrian first officer Elizabeth Singh in 2373, and the two started to have a relationship. (Star Trek: The Cantabrian Expeditions: "The Betrayed", "Whispering Into My Years of Pain").

Starfleet Intelligence discovered Galea was, in fact, working for the renegade Dr. Samantha Delaney as an information dealer. Starfleet assigned Singh to hunt him down and capture him, despite her feelings for him. In late 2373, Singh took Galea into custody. (Star Trek: The Cantabrian Expeditions: "For Queen and Country")

After being sentenced, he was incarcerated at the New Zealand Penal Settlement. (Star Trek: The Cantabrian Expeditions: "In the Still of the Night")