In the 1950s, the Ukrainian secret police launched several secret operations that targeted Jehovah’s Witness leadership and aimed to disclose Witness clandestine groups and their system of communication. The agent network was believed to be the main weapon in the fight against the religious dissent. There were about 200 agents and informers working in the Witness underground in the mid-1950s in western Ukraine. Most of them were recruited from within the Witness organization, many had tragic experiences with their close families imprisoned or exiled. Some of them had been and would be (after their service with the security police) arrested and tried. All of them were recruited by straightforward blackmail. However, as some historical accounts reveal, Witnesses were aware of agent infiltration and KGB surveillance and knew names of many agents and informers. They were also aware of some secret operations carried out against them. While being shadowed by the secret police, they shadowed KGB officers too. Counter-infiltration was another pattern of their everyday resistance. Some believers intentionally entered the informers’ network or were chosen to become collaborators by their own congregations. Appointed agents delivered partial or less sensitive information in exchange for getting to know KGB plans and operations. Other believers wrote fake denunciations to mislead the secret police.
The full account can be read here.
The 2002 Yearbook p. 192-193 also discusses this :
During the mid-1950’s, the security services discontinued immediate arrests of all active and responsible brothers and began to spy on them. These brothers were regularly called to the offices of the security services. They were told that they would receive money and enjoy a good career if they cooperated. Refusal to cooperate would lead to imprisonment and humiliation. A few, lacking faith in God, compromised on account of fear or greed. They remained in the ranks of the organization, informing the security services about the activities of Jehovah’s Witnesses. Also, they obediently carried out instructions from the authorities, causing innocent brothers to appear as traitors in the eyes of other faithful brothers. All of this promoted a spirit of distrust among many of the brothers.