Secretary of State Rex Tillerson Rex Wayne TillersonGary Cohn: 'I haven't made up my mind' on vote for president in November Kushner says 'Alice in Wonderland' describes Trump presidency: Woodward book Conspicuous by their absence from the Republican Convention MORE used an “alias email account” while CEO of Exxon Mobil Corp. to discuss climate change issues, the New York attorney general’s office alleged on Monday.

In a letter to a state judge, Attorney General Eric Schneiderman’s office said an investigation into the company’s climate science revealed Tillerson used an email account under the name “Wayne Tracker” between at least 2008 and 2015.

Schneiderman’s office had issued a subpoena for internal Exxon documents related to its investigation into the company’s knowledge of climate change.

ADVERTISEMENT

Officials told the judge that Exxon had not included emails from the “Wayne Tracker” account in its reply to the subpoena and that company officials hadn’t even acknowledged that the account existed.

“Tillerson used this secondary email address to send and receive materials regarding important matters, including those concerning to the risk-management issues related to climate change that are the focus of [the] investigation,” John Oleske, the senior enforcement counsel in the attorney general’s office, wrote.

The letter — part of an ongoing legal dispute between New York and Exxon, which Schneiderman has accused of misleading the public about its knowledge of climate change — was first reported by Bloomberg News. Exxon has denied the allegations against it.

An Exxon spokesman said the Wayne Tracker email account “is part of the company’s email system and was put in place for secure and expedited communications between select senior company officials and the former chairman for a broad range of business-related topics.”

The company said the account wasn’t only for discussing climate-related topics, and it noted, “the very fact the attorney general’s office has these emails is because they were produced in response to the subpoena.”

State Department officials did not respond to a request for comment.

News of Tillerson’s email account comes as the Trump administration weighs the future of the Paris climate deal, a major international diplomatic effort to cut carbon emissions. During his confirmation hearing in January, Tillerson told a Senate committee he thinks the United States should stay in the pact.

—This post has been updated.