Former Interior Secretary Ryan Zinke resigned in December amid scrutiny over his participation in a land deal with the chairman of Halliburton. | Shawn Thew - Pool/Getty Images energy DOJ investigating Zinke's use of personal email, inspector tells lawmakers

The Justice Department is investigating whether former Interior Secretary Ryan Zinke used personal email accounts for official business, a matter that has become part of a larger criminal probe into the departed official, according to a letter released by House Democrats on Tuesday.

The letter is the first public confirmation of a criminal investigation into Zinke, a former Republican congressman from Montana who faced scrutiny about his mixing of official, personal and political business while in President Donald Trump’s Cabinet.


The Interior Department's acting inspector general, Gail Ennis, told the lawmakers that the email investigation has been combined with an ongoing probe the IG is conducting with DOJ. That larger probe includes Zinke's participation in a land deal with the chairman of Halliburton, as well as Interior's obstruction of a tribal casino project in Connecticut following extensive lobbying by a rival casino company, both issues that were first reported by POLITICO.

House Natural Resources Chairman Raúl Grijalva and Oversight Chairman Elijah Cummings requested the email investigation in April 2018, when both were ranking members of their respective panels.

"Last year, the OIG began investigating the matter you presented contemporaneous to a related criminal investigation that we are coordinating with the Department of Justice," Ennis wrote to Cummings and Grijalva in her July 29 letter. "In consultation with DOJ and to avoid any interference with the criminal case, we have decided to combine the investigations. When we write our final report of investigation, we will include information that addresses the issues raised in your letter."

Zinke, who resigned in December, did not immediately respond to requests for comment. DOJ declined to comment.

Grijalva and Cummings welcomed the DOJ probe.

"This investigation and others like it are part of restoring public trust in government, which has suffered from the intentional destruction of the Trump years," Grijalva said in a statement. "Leaving office half a step ahead of the law doesn’t wipe the slate clean. It’s imperative that political appointees at the Department of Justice allow this investigation to continue unimpeded regardless of the risk to Mr. Zinke or other Trump officials."

