President Trump's personal assistant, John McEntee, was abruptly fired Monday over what are being described as "security" reasons, according to several news reports.

The New York Times is reporting McEntee apparently lost his security clearance, joining other White House staffers including Trump's son-in-law and senior policy adviser Jared Kushner who have seen their status downgraded in the wake of the Rob Porter scandal.

Revelations that Porter, the White House staff secretary, had access to classified information despite accusations of domestic violence against him prompted a review of security procedures within the White House.

Other outlets, including CNN, were reporting that McEntee was being investigated for "serious financial crimes."

The Wall Street Journal, which first reported McEntee's firing, said he was escorted out of the White House Monday.

News of McEntee's departure came on an especially tumultuous day for the White House. Trump fired Secretary of State Rex Tillerson Tuesday. Steve Goldstein, undersecretary of State for public diplomacy, was also dismissed for giving reporters differing accounts of how the secretary of State learned of his fate.

Rep. Elijah E. Cummings, D-Md., the top Democrat on the House Committee on Oversight and Government Reform, sent a letter to White House Chief of Staff John Kelly within hours of McEntee's firing, requesting documents relating to McEntee's firing and questions about his security clearance.

“This recent report about President Trump’s personal assistant is just the latest indication that the process for vetting White House employees for security issues is seriously flawed,” Cummings wrote. “The White House’s ongoing obstruction of congressional oversight appears to be an attempt to conceal from the American people pervasive and widespread dysfunction inside the White House, which directly threatens our nation’s security.”

A call to a phone number listed as McEntee's was not answered Tuesday afternoon.

The former University of Connecticut quarterback had gained a measure of fame on social media for a video of trick shots he performed several years ago.

White House officials said McEntee was leaving to join Trump's 2020 reelection campaign.