New York state Attorney General Eric Schneiderman says U.S. Secretary of State Rex Tillerson, the former CEO of ExxonMobil, used an alias email address for several years to send out messages about climate change, Reuters reported Monday. The claim comes as the state AG continues to investigate Exxon for allegedly intentionally misleading the public on climate change in a bid to hide risks from investors. A letter sent by Schneiderman to a New York judge overseeing the investigation says the email address was in use for several years but was not previously disclosed, according to the report. The email address, registered under the pseudonym “Wayne Tracker,” was in use from 2008 to 2015, Schneiderman said. “Exxon’s top executives, and in particular, Mr. Tillerson, have made multiple representations that are at the center of [attorney general’s office] investigation of potentially false or misleading statements to investors and the public,” Schneiderman said. The State Department has yet to comment on the matter, but an Exxon spokesman was cited as saying the email address was “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 spokesman, Alan Jeffers, said Exxon had already provided 2.5 million pages of documents as part of Schneiderman’s investigation and would respond to the claims in court filings. Exxon had previously provided about 60 documents related to the “Wayne Tracker” email account, though it never mentioned it was used by Tillerson, Schneiderman said. The letter asked the judge to seek explanation from Exxon on whether emails sent and received by “Wayne Tracker” had been preserved, and to identify any other accounts used by Tillerson.