Prosecutor General's Office of Ukraine (PGO) has said it has no information which proves the involvement of officers of the Russian Federal Security Service (FSB) in the shooting of Maidan protesters during the Revolution of Dignity in response to the allegation of former chief of the Security Service of Ukraine (SBU) Valentyn Nalyvaichenko.

"Nalyvaichenko continues to insist that he gave the PGO all data that indicates that FSB representatives controlled snipers on Maidan. It's not the way as it is," chief of the PGO special investigations directorate Serhiy Horbatiuk said in Kyiv on Tuesday.

Horbatiuk has called Nalyvaichenko in for questioning as a witness to provide evidence to substantiate his allegation.

"In order to prevent any rumors, we are inviting Nalyvaichenko for an interrogation as a witness and then he could demonstrate and explain, with all supporting documents, where he could see the evidence," Horbatiuk said.

Still, the detectives of the Ukraine's PGO, who are investigating the Maidan events, do not exclude any versions including possible involvement of any individuals or security services in the events and this information is being verified and studied attentively, Horbatiuk revealed. "But such unsubstantiated allegations, which look like PR actions in favor of certain politicians in the first place, they by no means facilitate, but impede the investigation into the events on Maidan," he said.

However, Horbatiuk stressed that according to the information possessed by the Prosecutor General's Office of Ukraine, several officers of the Russian security services were present at the time on Kyiv's Maidan, but "for information purposes" only.

"These people arrived during December and January, received information from SBU officials in relation to current developments in Maidan. That is, their first priority of interest was the course of events, the way in which Maidan was created, how it was financed and other things concerning the protests groups: how they interacted," Horbatiuk said.

Meanwhile, the mere fact of their presence in Ukraine is not a crime for they had legally entered Ukrainian territory and legally left it, he said.

Nonetheless, a probe was launched into the fact of the handover of the information by SBU officials to Russia's FSB and a number of Ukrainian security officers were notified of suspicion. "I won't tell the details as the case is being probed by the Main Military Prosecutor's Office," Horbatiuk said.