The Athens News Agency (ANA) reported that the Greek authorities had "tracked a Russian mafia group that committed robberies and contract killings in Greece."
The police said the criminal group had been responsible for the killings in Greece of at least three immigrants from former Soviet republics over the past four years and were currently in "hiding in Russia."
The Greek authorities have issued international arrest warrants for the criminals and are currently seeking their extradition to Greece, with one of the suspects "currently in custody in a Russian prison for membership of a criminal group," the channel said.
Investigators said each murder cost 20,000 euros and was linked to cigarette, alcohol and oil smuggling.
The suspects' names have not been disclosed yet.