Image: YLE / Erno Serkosalmi

The "hacktivists" are particularly perturbed by the company exceeding emissions caps at its mining site in Sotkamo in the Kainuu region.

“Waste water from the mining site may have affected ground water in the whole area,” states the release.

Finnish police are probing whether miner Talvivaara committed a crime when discharging waste water with high levels of sodium, sulphate and manganese into lakes near its nickel mine in eastern Finland.

Anonymous is suspected to have orchestrated last weekend's massive data leak that published the personal details of nearly 16,000 Finns.