"Highly professional FSB officers are working there. They have experienced the same tricks during the two Chechen wars. Chechens used these methods against them, when the poor officers were bribed, and ended up blatantly betraying troops, when the commanders deliberately sent whole battalions under artillery fire," Tuka told Ukrainska Pravda.

Tuka described the model in the following way: at first, a person is allowed to earn some money, after that he is squeezed for handing over secret information, after that he is under control.

"It comes to such ridiculous things that our boneheaded officers do not even realize what risk they are at when they get some money for their services in cash and the rest is transferred onto their bank cards with their names on them," he said.

In the end, they are blackmailed into agreeing to cooperation with the Russian security service.

"There are facts of both fraternizing [with the enemy] and striking cozy deals – we've got everything now," he said.

As UNIAN reported earlier, seven joint mobile groups have been fighting against smuggling in the Donbas conflict zone. The groups consist of personnel from the SBU Security Service of Ukraine, the State Fiscal Service of Ukraine, the Interior Ministry, the State Tax Service of Ukraine, law enforcement agencies, and representatives of volunteer organizations.