Russia said on Friday a decision by a Greek court to clear the way for a suspected Russian money launderer to be extradited to the United States was a violation of international law.

Russia has also lodged an extradition request and its Foreign Ministry said on Friday that submission should take priority because the suspect, Alexander Vinnik, is a Russian citizen.

A Greek court cleared the way on Wednesday for Vinnik, the alleged mastermind of a $4 billion bitcoin laundering ring, to be sent to the United States where he faces up to 55 years in prison.

Vinnik, who denies the charges against him, is one of seven Russians arrested or indicted on U.S. cybercrime charges so far this year.

“We believe the (Greek) verdict is unjust and violates the basics of the international law,” the Russian ministry said in a statement.

The Greek court’s decision could be appealed and must ultimately be approved by the Greek Justice Minister, Stavros Kontonis.

A hearing date for the Russian extradition request has been set for Oct. 11, RIA news agency cited Vinnik’s lawyer as saying. Vinnik also denies the Russian charges but has agreed to be sent back to Russia.

The full statement by the Russian Foreign Ministry:

”We have noted with regret the decision of the appellate court in Thessaloniki, Greece to comply with a request from the United States to extradite Alexander Vinnik to the US.

We deem the verdict unjust and a violation of international law. A request from the Russian Prosecutor General’s Office on extraditing Mr Vinnik to Russia was submitted to the Greek authorities. Based on legal precedent, the Russian request should take priority as Mr Vinnik is a citizen of Russia. The verdict is even more surprising in the context of the atmosphere of friendly relations between Russia and Greece.

We proceed from the fact that this court decision is not final. Mr Vinnik’s council will appeal to the Supreme Civil and Criminal Court of Greece. The court’s verdict must then be submitted to the Greek Minister of Justice for approval.

We hope the Greek authorities will consider the Russian Prosecutor General’s Office request, and Russia’s reasoning, and act in strict compliance with international law”