An advisor to the Ukrainian interior minister, Anton Herahchenko, has said that former Ukrainian officials - Viktor Yanukovych, Mykola Azarov and Viktor Pshonka, as well as their families – have received Russian citizenship.

"The families of Yanukovych, Pshonka and Azarov have managed to agree with [Russian President Vladimir] Putin on the provision of Russian citizenship, and they may still feel dry and comfortable. I learned from operational sources that [Russian] nationality to Ukraine's betrayers had been granted under a separate secret decree of Russian President Vladimir Putin as a reward for their faithful service on the collapse of [Ukraine's] national security, defense, law and order system and economy," he wrote on his Facebook page on Friday.

He noted that according to the Russian Constitution, "Russia does not give its citizens to anyone, be they serial killers or maniacs."

"Besides, in the same way as Ukraine does," he added.

In this regard, Heraschenko said he was in favor of amending the constitution and law "in terms of depriving betrayers of nationality."

As reported, a number of officials left Ukraine after many protesters were killed on Independence Square in Kyiv in February 2014. In particular, former President Viktor Yanukovych, former Prime Minister Mykola Azarov, former Prosecutor General Viktor Pshonka and former Interior Minister Vitaliy Zakharchenko left for Russia. A number of criminal cases were opened against them.