The Associated Press reports that as many as 600 miners - which have yet to be recovered - were stolen during four separate incidents in December and January.

Eleven people, including a security worker, have been arrested in connection with the investigation into what has been called the "Big Bitcoin Heist." Two of those arrested remain in custody after a Reykjanes District Court ruling, though it is unclear what role they allegedly played in the heists.

Officials in Iceland reportedly said the scheme to steal the machines, which are worth close to $2 million, is the biggest in the island nation's history. Police commissioner Olafur Kjartannson, who works in the southwestern Reykjanes region where two of the thefts took place, said they were "on a scale unseen before."

"Everything points to this being a highly organized crime," he said.