Ukrainian police will conduct pre-investigation checks on the circumstances of events that took place in Kyiv involving Russian opposition member Leonid Razvozzhayev only if there is a respective address or statement about unlawful actions against this citizen, the media liaisons office of the Ukrainian Interior Ministry has told Interfax-Ukraine.

The police have currently received no statements of this kind.

"In order to establish the truth of this matter, it is necessary to conduct pre-investigation checks, in particular, to establish when he crossed the border, and how," the ministry said.

The ministry said that such pre-investigation checks could be conducted only if there is a statement about unlawful actions against a person. The police have currently received no similar complaints about it.

The press service of the Ukrainian left-wing organization Borotba circulated a statement on Saturday, saying that Razvozzhayev had been in Kyiv legally since October 17.

"Leonid turned to international organizations, requesting political asylum, and he filled a form and submitted it to the Kyiv office of the UN Refugee Agency. After he left the building, the UN staff heard calls for help. No one has heard of him since then and he has not been answering telephone calls," Borotba said.

Razvozzhayev may have been detained by special services "without any lawful reasons and he will be moved to Russia in violation of the UN Convention on Refugees," it said.

Razvozzhayev's Ukrainian defense lawyer informed police in Kyiv about his client's disappearance.

Meanwhile, the Kyiv police said they have no information to confirm that Razvozzhayev has been detained.

Russia's Investigative Committee launched proceedings on October 17 against Russian opposition leader Sergei Udaltsov, his assistant Konstantin Lebedev and Razvozzhayev, who is an aide to State Duma deputy Ilya Ponomaryov, accusing them of plotting mass riots.

The proceedings followed investigations into allegations in the film "Anatomy of Protest 2," shown by Russia's NTV television on October 5.

The day the proceedings against them officially started, Udaltsov and Lebedev were interrogated at the Investigative Committee and had their apartments searched by detectives.

Udaltsov was released with travel restrictions, but Lebedev was put under 48 hours' arrest and the next day had his term of detention extended by court order until December 16, as sought by investigators.

Investigators, however, were unable to find Razvozzhayev, the committee said.

Udaltsov and Lebedev said during the interrogation that they had nothing to do with the riots they were blamed for, but confirmed that they had meetings in Minsk, capital of Belarus, in summer this year with nationals of Georgia.

Udaltsov called the proceedings against him a political move.

Razvozzhayev was put on Russia's national wanted list, Investigative Committee spokesman Vladimir Markin told Interfax on August 19.