New York’s Attorney General Eric Schneiderman issued a subpoena against Exxon Mobil Wednesday evening citing possible lies to the public by the energy giant about the risks associated with climate change. The New York Times first reported the news citing people familiar with the matter.
The subpoena reportedly dates back to activities by the company stemming over the last 40 years, focusing on whether or not the company “adequately warned investors about potential financial risks stemming from society’s need to limit fossil-fuel use,” according to the newspaper.
“We unequivocally reject the allegations that Exxon Mobil has suppressed climate-change research,” Kenneth P. Cohen, vice president for public affairs at Exxon Mobil Cohen, said in an interview with the Times.
The newspaper noted that the investigation may include other oil companies in the future.
Per the publication:
Whether Exxon Mobil began disclosing the business risks of climate change as soon as it understood them is likely to be a major focus of the New York case. The sources said the investigators for the attorney general were poring through the company’s disclosure filings since the 1970s.
Exxon Mobil has been disclosing such risks recently. Last year, for example, it warned investors of intensifying efforts by governments around the world to limit emissions.
Fortune has reached out to the Attorney General’s office for comment.