The attorney general of New York is investigating whether Exxon Mobil lied to the public and investors about the risks of climate change, the Texas oil giant confirmed late Thursday.

Eric Schneiderman, the attorney general, subpoenaed the oil company Wednesday seeking e-mails, financial records, and other materials like communications with trade and industry groups.

At its core, the probe is about determining whether the world's biggest oil exporter's own scientific research meshes with what the oil company has publicly said to investors—and the inquiry stretches back decades. The issue hearkens back to Big Tobacco's suppression of data about the health consequences linked to smoking. The legal action, moreover, comes in the wake of a series of reports by The Los Angeles Times alleging that, for decades, Exxon and its worldwide affiliates "were crafting a public policy position that sought to downplay the certainty of global warming."

Exxon Mobil spokesman Ken Cohen said the company "unequivocally" rejects assertions that it suppressed climate change research concerning whether reducing fossil fuel use was needed to combat global warming.

"We are proud of our record of disclosing to investors and the investment community what we believe are material facts applicable to our business," Cohen told reporters during a conference call late Thursday.

Exxon is among the world's leading producers of carbon-heavy energy. If it had research showing that reducing oil consumption could mitigate global warming, that is evidence required to be shared with investors. Public companies must disclose to investors issues that could have a "material impact" on their bottom line, according to stock market rules.

Cohen said the company has not misled investors in its 10-K financial filings and elsewhere.

Greenpeace applauded the attorney general's move.

“This subpoena on Exxon Mobil is groundbreaking news. The oil giant’s ongoing public climate denial is something that should concern us all, and has rightfully attracted the attention of the country’s judicial watch dogs," said Annie Leonard, the Greenpeace USA executive director. "New York Attorney General Schneiderman is leading the charge to further expose the hypocrisy of fossil fuel companies like Exxon Mobil and hold them accountable for denying climate change to the public and blocking necessary action for decades."

The attorney general's office declined comment.