New York Attorney General Eric Schneiderman served ExxonMobil with subpoenas last Wednesday evening, the first step in determining whether the fossil giant misled the public about the risk of climate change and its impact on its business.

“The investigation focuses on whether statements the company made to investors about climate risks as recently as this year were consistent with the company’s own long-running scientific research,” the New York Times reports. Sources familiar with the investigation “said the inquiry would include a period of at least a decade during which ExxonMobil funded outside groups that sought to undermine climate science, even as its in-house scientists were outlining the potential consequences—and uncertainties—to company executives.”

“We unequivocally reject the allegations that ExxonMobil has suppressed climate change research,” said Exxon’s Vice President for Public Affairs, Kenneth P. Cohen.

The Times and ClimateProgress both reported that Schneiderman is also investigating whether Peabody Energy, the largest coal producer in the United States, properly disclosed the financial risks it faces due to climate change.

“To date, lawsuits trying to hold fuel companies accountable for damage they are causing to the climate have failed in the courts, but most of those have been pursued by private plaintiffs,” Gillis and Krauss write. “Some experts see the potential for a legal assault on fossil fuel companies similar to the lawsuits against tobacco companies in recent decades, which cost those companies tens of billions of dollars in penalties.”

Pulitzer Prize-winning InsideClimate News, which broke the original story about Exxon’s climate research dating back to the mid-1970s, carried the reaction to Schneiderman’s announcement.

Meanwhile, ClimateTruth.org is out with a petition urging U.S. Attorney General Loretta Lynch to “investigate ExxonMobil for deliberately deceiving the public about climate change.”