By Natalia Zinets
KYIV (Reuters) - Ukraine on Friday announced sanctions on Viktor Medvedchuk, a prominent opposition party leader with ties to the Kremlin, and also said it was taking back into state hands a pipeline that transports Russian oil products to Europe.
Medvedchuk's office did not immediately respond to a request for comment.
But a statement from Medvedchuk's party on Facebook said: "Today, Ukraine is one step closer to becoming a dictatorship."
A wealthy businessman, Medvedchuk is a Ukrainian citizen but has close ties with Russian President Vladimir Putin and has said the Russian leader is godfather to his daughter.
His links to Russia are a problem in Ukraine as relations between the two countries collapsed following Moscow's annexation of Crimea in 2014 and support for separatists in the conflict in eastern Ukraine.
Sanctioning Medvedchuk follows Ukraine's move at the start of the month to sanction several TV stations owned by an associate of Medvedchuk that Kyiv says were part-financed by Moscow.
Medvedchuk had said the sanctions on the media outlets were illegal.
At a briefing on Friday evening, Oleksiy Danilov, secretary of the National Security and Defence Council, said the security services were investigating Medvedchuk on suspicion of financing terrorism.
Ukraine's state security service (SBU) said the sanctions were linked to its investigation into how coal from mines in the separatist-held Luhansk region was sold to Russia and government-controlled Ukraine.
Danilov said the sanctions would include a freeze on Medvedchuk's assets but said a full list of measures would be disclosed in a special presidential decree that has not been published yet.
The Kyiv authorities also said they were taking back into state hands the PrykarpatZakhidtrans oil product pipeline.
President Volodymyr Zelenskiy's office said the pipeline officially had two owners registered abroad but was "affiliated with two citizens of Ukraine".
"Having considered this issue, the National Security and Defence Council decided to take urgent measures to return the state property to the people of Ukraine. Law enforcement agencies are also tasked with investigating the circumstances in which state property fell into private hands," it said.
Ukrainian media have previously suggested the pipeline was under Medvedchuk's control.
(Writing by Matthias Williams; Editing by Richard Chang and Barbara Lewis)