Police said Wednesday they have booked three South Koreans without physical detention on charges of stealing a thermal observation device from a U.S. unit’s military equipment storage and attempting to sell it online.

A 56-year-old waste management employee working at a U.S. Army base in Gunsan, 274 kilometers south of Seoul, is suspected of stealing the TOD, estimated to be worth about 100 million won ($93,100), in March and selling it to a military equipment dealer for just 50,000 won, the Seoul Metropolitan Police Agency said.

The dealer allegedly handed the TOD over to an online seller for 1 million won, who later placed the TOD on sale at an international auction site for $9,900, the agency said.

Police tracked the suspects down while widening their probe into those who sell military equipment online. They confiscated the camera and returned it to the U.S. military, officials said.

“Lee could easily steal the camera as he frequented the unit and knew the inside of the unit well,” a police official said. “Lee sold the camera for only 50,000 won because he didn’t know that the camera was an important piece of equipment.”

The TOD is a piece of strategic military equipment deployed in front-line troops and major facilities for surveillance and targeting at night. It needs South Korean government approval to be exported overseas. (Yonhap News)