Around 600 computers used to mine bitcoin were stolen in Iceland in a series of large-scale heists in December and January, police said Wednesday.
The servers were taken from data centres in Reykjanesbaer, near the Keflavik international airport in southwestern Iceland, and Borgarnes on the west coast.
Around 10 people were brought in for questioning, and two Icelanders in their 20s and 30s are currently in detention suspected of involvement in the crime, a police spokesman for southwestern Iceland told AFP.
He suggested the thefts could be linked to organised crime.
"Everything points in that direction," he said.
Bitcoin is a virtual currency created from computer code that allows anonymous transactions.
The thieves may have wanted to use the stolen equipment to "mine", or create, bitcoin - a lucrative affair but one which requires advanced and expensive equipment.
Investigators are still trying to locate the missing equipment, which is valued at around 200 million kronur (1.6 million euros, $2 million).
The theft is one of the biggest ever seen in Iceland.
Bitcoin's value has soared since it came into being in 2009, though it has more than halved in recent months. On December 16 it was valued at $19,377, compared to today's $10,500.
Iceland has become a magnet for cryptocurrency farms, blockchain technologies and data centres because of its cold climate which is instrumental in cooling the energy-consuming servers, and its low electricity prices.