TAIPEI (Taiwan News) — Four officers of Taiwan’s Marine Corps were detained after a Stinger missile launcher turned up in the arsenal of a criminal gang, reports said Tuesday (Oct. 24).

Prosecutors found the launcher, a used older model from 2009, during a raid on an organized crime group, the China Times reported. The investigation led to four officers at the 66th Brigade of the Marine Corps and a civilian.

The Taoyuan District Prosecutors Office raided three locations in Taoyuan and in south Taiwan on Monday (Oct. 23) and started questioning the suspects overnight. There was a possibility that the case would expand to include more individuals.

On Tuesday morning, prosecutors filed a request with a court to detain the four officers. The fifth suspect was freed on bail of NT$100,000 (US$3,100) Tuesday morning, per the Liberty Times.

The FIM-92 Stinger is a shoulder-fired surface-to-air missile for short-range attacks on drones and low-flying aircraft. Taiwan reportedly received the first of its Stingers early this year.