Ukrainian Navy flagship Hetman Sahaidachny has reportedly refused orders from Kiev and defected to the Russian side, a Russian senator has claimed in an interview with Ivestia Daily.

"Ukraine’s Navy flagship the Hetman Sahaidachny has come over to our side today. It has hung out the St Andrew’s flag," Sen. Igor Morozov, a member of the committee on the international affairs, told Izvestia. "The crew has fulfilled the order by the chief commander of Ukraine’s armed forces Viktor Yanukovych."

The ship recently took part in counter-piracy patrols with EU naval forces and was sailing towards its homeport of Sevastopol, Naval Today reports.

However, Ukraine media is denying the reports, which have only appeared in Russian sources.

"Ukraine's Naval Forces ships are in their home bases, except for the flagship frigate Hetman Sahaydachniy, which is returning from a six-month stay in the Gulf of Aden, and is now at NATO's Souda Bay base in the Mediterranean," one report stated on Sunday.

It's not yet clear which side is correct, as the Ukraine Navy is in considerable turmoil. In the presence of the pro-Russian leader on Sunday, the newly-appointed head of the navy has sworn allegiance to the Crimea region, BBC reports.

Ousted Ukraine President Yanukovych, under Kremlin protection in the Russian city of Rostov-on-Don, railed against those who forced him out of power in a press conference on Feb. 28, calling them "radical mobsters" who took over the country.

"I believe that the Ukrainian parliament is not legitimate," he said.

This post has been updated.