The Security Service of Ukraine (SBU) said it had uncovered contacts between Stepan Kaplunov, deputy commander of the Russian Volunteer Corps (RDK), and Russia's Federal Security Service (FSB). According to the agency, Kaplunov was tasked with preparing an assassination attempt on "one of the leaders of the Russian opposition movement" who planned to visit Ukraine, as well as on other Ukrainian service members, in exchange for money.

The SBU released a video in which Kaplunov admits to contacts with an FSB representative and says the officer tried to recruit him. The agency claims he confessed to the contact and provided information that helped identify others involved in planning the crime. The SBU's Telegram channel also published screenshots of messages from Kaplunov's phone, in which an unidentified person offers him "to two-hundred someone in Ukraine for from $50k per person" (spelling preserved).

Kaplunov, whom the RDK says was abducted, gives a different account. In an interview with Ukrainian Radio NV, he said that on August 23, unknown men posing as police attacked him near his home, handcuffed him, and took him to a "secret prison." He said there was no physical force, but he was threatened that he "could disappear forever." He claims he gave testimony about cooperating with the FSB under pressure and denies any contacts with the Russian side.

In a video address published on the RDK's Telegram channel, Kaplunov said he was used to discredit Dmitry Ivanov, deputy commander of the special unit "Timur," and Kyrylo Budanov, head of Ukraine's military intelligence (GUR). He said they wanted to "stick cooperation with the FSB" on them. The RDK also published a recording from the entrance of Kaplunov's building, claiming that unknown people tried to enter his apartment to "plant unknown items."

The scandal escalated after a nighttime shootout between SBU and GUR officers on September 2. According to Kaplunov's lawyer, the conflict occurred when Kaplunov was brought to his home for searches, where GUR colleagues were already present. The situation was resolved after the SBU agreed to release Kaplunov.

Ukrainian President Volodymyr Zelensky called the situation between the SBU and GUR units "utterly disgraceful" and demanded personnel decisions. "Shooting here, in Ukraine, can only be done at Russian occupiers to defend Ukraine," he said.