Federal prosecutors have subpoenaed the state of North Carolina for reams of state documents and are ordering 20 state environmental agency employees to testify before a grand jury following a massive coal ash spill in the state earlier this month.

According to The Associated Press, the subpoenas were made public by the NC Department of Environment and Natural Resources (DENR) on Wednesday. Prosecutors have also ordered state officials to disclose any records “pertaining to investments, cash or other items of value they might have received from Duke Energy or its employees.”

On February 2, a pipeline running under a coal ash pond at Duke Energy’s Dan River facility began leaking tens of thousands of tons of coal ash into the Dan River in North Carolina. Residents began noticing that the river appeared black, though Duke did not report the spill until Monday afternoon, 24 hours after the leak was discovered. Duke has also been served with a new subpoena.

Residents of Danville, Virginia withdraw their drinking water 6 miles downstream from the site of the leak. Coal ash leaked up to 70 miles downstream, and state health officials have advised residents not to touch the water or eat fish from the river, The AP reports.

Environmental groups have made multiple efforts to file citizen lawsuits against Duke Energy to force the company to clean out its toxic coal ash dumps. In 2009, an EPA investigation found Duke’s 53-year-old Dan River ash pond dams to be “high hazard,” noting “continued movement” and “seepage” on the bank of the primary ash basin facing the river.

Those efforts were thwarted by the state DENR, which three times blocked citizen lawsuits against Duke by intervening. The relationship between state regulators and energy companies has reportedly become cozier since the election of Gov. Pat McCrory, a pro-business Republican and a former Duke employee of 28 years.

Since McCrory’s first unsuccessful gubernatorial campaign in 2008, Duke Energy, its PAC, and its executives have donated at least $1.1 million to McCrory’s campaign and affiliated groups that supported him. After winning the 2012 election, McCrory appointed other former Duke employees including Secretary of Commerce Sharon Decker.

McCrory also appointed current State Environmental Secretary John Skvarla, whom environmental groups have suggested may have “shepherded a ‘sweetheart deal’ for McCrory’s former employer,” according to The AP. Citizens have asked that Duke remove coal ash from its unsealed, leaking pits to sealed landfills capable of handling toxic waste.

In a local television interview Wednesday, McCrory said his preference was for Duke to remove its dumps, but that other options would also be considered. Echoing a contention made earlier by [Skvarla], the governor suggested scooping out the toxic ash and hauling it away might actually cause more environmental harm than leaving it in place… Asked for a real-world example or scientific study suggesting that moving toxic ash away from rivers and lakes might be harmful, staff at the state environmental agency did not provide one.

Environmental watchdog groups Waterkeeper Alliance and Yadkin Riverkeeper have offered a $5,000 reward to anyone who provides new evidence that could lead to charges relating to the recent coal ash spill in the Dan River. Waterkeeper Alliance noted that the state’s water sampling returned different results from its own, which showed that arsenic levels in the water were unsafe. According to both groups, the state’s actions regarding the spill have bred mistrust.

“Duke could have avoided contaminating the Dan River in North Carolina and poisoning Virginia’s water supplies if it had removed its toxic ash heaps years ago after being warned by the EPA,” said Robert F. Kennedy, Jr., the president of Waterkeeper Alliance. “Environmental crime is not a victimless crime.”

“The poisoning of the Dan River is an act of theft at the very least,” he added. “North Carolina’s constitution provides that the people of North Carolina own the waterway, but Duke Energy has now illegally privatized it.”

Alisha is a writer and researcher with Ring of Fire. You can follow her on Twitter @childoftheearth.