Military counterintelligence agents from Ukraine's SBU State Security Service have uncovered a National Guard lieutenant colonel with Russian citizenship, who earlier collected information on a USB flash drive in the then Anti-Terrorist Operation (ATO) headquarters about National Guard battle missions.

The SBU's press center said on Wednesday that SBU agents collected evidence showing that in 2014 the man supported the so-called "Russian world" ideology. He traveled to Russia-occupied Crimea and received Russian citizenship, a driver's license, registered for military service and followed the procedure for receiving a Russia military pension, because he fought for the aggressor country in 1995 in military actions in Russia's Chechnya Republic.

SBU agents established that in 2016 the lieutenant colonel began serving in the main directorate of Ukraine's National Guard with the assistance of former National Guard leaders. He received a security clearance and applied to National Guard leaders to be sent to the ATO area in eastern Ukraine.

"Located at ATO HQ, the lt. colonel, in violation of established secrecy regulations, collected on USB flash drives a large amount of secret information about the fulfillment of battle missions of National Guard units in the ATO," the SBU said.

In order to prevent a leak and publication of the information that is a state secret, SBU military counterintelligence agents seized the storage devices. The lt. colonel has been released from fulfilling his duties. The evidence gathered regarding him been given to investigators in charge of the pretrial investigation.