Greek law enforcement has disrupted a plan to murder a Russian man arrested in Greece last year, who American authorities believe laundered billions of dollars' worth of Bitcoin through BTC-e, a shady Bitcoin exchange that the suspect is also accused of creating.

Sputnik News, a Russian media outlet, quoted an anonymous source "familiar with the situation" who said that local criminals were plotting to poison the Russian suspect, Alexander Vinnik. He is reportedly now "forbidden" from receiving any items and cannot even contact other inmates.

Last summer, federal authorities identified Vinnik as a central figure in the massive bitcoin theft that was a major factor in the downfall of Mt. Gox, the Japanese Bitcoin exchange that led the market in Bitcoin's early years. If Vinnik is ultimately determined to be involved in the crash and eventual bankruptcy of Mt. Gox, that revelation would finally solve what has remained one of the Bitcoin commnity’s biggest mysteries.

Sputnik’s source was quoted as saying that the threats began "after Vinnik’s extradition to the United States was blocked. There are people who are extremely interested in him not coming to Russia. The assassination was ordered by some unknown person from Russia."

In December 2017, the Supreme Court of Greece upheld American efforts to have him extradited to the United States.

Sputnik’s source further said that Vinnik has admitted his crimes and is "ready to give testimony in Russia and assist the investigation."

However, per the Russian media outlet, Vinnik’s lawyer planned in January 2018 to appeal the extradition order to the European Court of Human Rights.