Duke Energy is asking a North Carolina judge to shield its records from state regulators and environmental groups while a federal criminal investigation is ongoing.
According to a court document, the company told a judge in a motion last week that providing the requested records about activities at its North Carolina coal ash dumps could hurt the integrity of the federal investigation.
Federal prosecutors in Raleigh have issued 23 subpoenas as part of a widening criminal probe triggered by the Feb. 2 spill at Duke's plant in Eden, which coated 70 miles of the Dan River in toxic sludge.
In the last month, state regulators have issued nine environmental violations against Duke because of the spill and issues at other plants.
Duke's motion deals with state enforcement action at Charlotte-area and Asheville waste pits.