New York Attorney General Eric Schneiderman said Tuesday Mar. 14 that Secretary of State Rex Tillerson used an email alias while CEO of Exxon to discuss climate change.

The alias, Wayne Tracker, was used from 2008 to 2015. Schneiderman made the claim and has accused Exxon for not turning over all relevant documents required by a court order.

Exxon has been in a protracted legal dispute in which the company is fighting off investigations looking for evidence that Exxon misled investors about the impact of climate change.

Mr. Tillerson, who was Exxon’s CEO at the time, claims through a spokesman that the secret alias was used for “secure and expedited communications between select senior company officials and the former chairman for a broad range of business-related topics.” However, Schneiderman argues that this email account was never disclosed.

“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 email account was a vehicle for Mr. Tillerson’s relevant communications at Exxon, and no documents appear to have been collected from this email account,” Schneiderman said.

Despite this, the company contends that the email account was not just used to discuss climate change, but also a broad range of business matters.

The account was “mostly used while he [Tillerson] was traveling to ensure he’d see an item in a secure and timely way without having to sort through his regular email inbox, which could contain many items. To suggest it was exclusively or even primarily about climate issues is absolutely false and misleading,” said company spokesman Alan Jeffers.