Exxon Mobil CEO Rex W. Tillerson addresses reporters at a news conference at the conclusion of the Exxon Mobil Shareholders Meeting in Dallas, Texas May 27, 2009. Reuters/Jessica Rinaldi

Secretary of State and former Exxon Mobil CEO Rex Tillerson used an alias email address to talk to other Exxon officials about "important matters, including those concerning to the risk-management issues related to climate change," according to a letter sent to a judge by the office of New York Attorney General Eric Schneiderman and published by Bloomberg on Monday.

The discussions over Exxon Mobil's climate-change risk-management is the focus of New York's inquiry into the oil company. Schneiderman's office uncovered the information as part of its investigation, which found Tillerson allegedly used the email pseudonym "Wayne Tracker" – Wayne is Tillerson's middle name – for at least 7 years, from 2008 to 2015.

Schneiderman alleged the information should have been disclosed to his office, and that Exxon never did so, even though the oil company had over 60 emails originating from that address in its system. The letter comes as Schneiderman's office is investigating Exxon for allegedly covering up its knowledge of the risks of climate change from the public.

"Despite the company’s incidental production of approximately 60 documents bearing the ‘Wayne Tracker’ email address, neither Exxon nor its counsel have ever disclosed that this separate e-mail account was a vehicle for Mr. Tillerson’s relevant communications at Exxon, and no documents appear to have been collected from this email account," the letter, which was signed by senior enforcement counsel John Oleske, said.



Climate activists and environmentalist groups are incensed by the discovery.

"This is big. Tillerson's use of a secret email account underscores what we've been saying all along: Exxon knew their product causes climate change, but buried the truth in order to protect their profits," said a spokesperson for 350.org, an environmentalist group.

She added, "If they had nothing to hide, then why the secret email account? This sort of discovery should prompt even more Attorneys General, like California's Xavier Becerra, to get in on this investigation. 'Wayne Tracker' is just the tip of the melting iceberg here -- there's likely far more deception just below the surface."

"Rex Tillerson might have questioned climate change as CEO of ExxonMobil, but it seems that Wayne Tracker understood its risks quite well. Who is Wayne Tracker? The alias Tillerson used at Exxon to send emails about climate risks, according to New York Attorney General Eric Schneiderman," said a spokesperson for Greenpeace.

The spokesperson continued: "This is a significant development in Schneiderman’s investigation into what Exxon knew about climate change, when it knew it, and what the company did to conceal it. Was Rex Tillerson that worried about climate risks for Exxon? Or was he more worried about the risk of revealing them to his shareholders and to the public? Or was it both?"

In light of uncovering Tillerson's alleged alias, Schneiderman's office wrote to New York judge Barry R. Ostrager asking that the court order Exxon to be more transparent about its past practices and produce any and all relevant documents in addition to the ones already provided.