MOSCOW (AP) — Russia’s main criminal investigation body has launched a probe after a report that a nickel-processing plant was pumping water contaminated with heavy metals into the Arctic tundra. The reported pollution detailed Sunday by the Novaya Gazeta newspaper was in the same region where a massive diesel spill last month entered Lake Pyasino, which feeds into the Arctic Sea. The newspaper released a video of what it said was water from a Norilsk Nickel enrichment plant gushing out into a river that also runs into the lake. The Investigative Committee branch said it has sent investigators. Norilsk Nickel, one of Russia’s biggest companies, also owns the power plant from which 21,000 tons of diesel fuel leaked in May.