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White House Staff Secretary Rob Porter could be leaving the Trump administration as early as Thursday, a source told Fox News, amid questions over the internal handling of domestic abuse allegations against him.

Porter, who denies the allegations, announced his resignation on Wednesday and had been expected to stay on for a period of time to ensure a smooth transition. But with photos circulating showing one of his two ex-wives with what appears to be a black eye, the departure could be moved up.

The case also has raised questions for Chief of Staff John Kelly, who initially defended Porter. New reports say some aides were aware of the allegations for months.

Kelly now says he was “shocked” by the new accusations against the senior Trump aide.

Kelly said: “There is no place for domestic violence in our society. I stand by my previous comments of the Rob Porter that I have come to know since becoming Chief of Staff, and believe every individual deserves the right to defend their reputation. I accepted his resignation earlier today, and will ensure a swift and orderly transition."

DailyMail.com first published a photo of one ex-wife’s bruised face. Colbie Holderness told the outlet that Porter choked and punched her during their marriage.

Holderness told Fox News on Thursday that she got the black eye during a hotel-room fight when she and Porter were on vacation in Florence, Italy. Further, Holderness said she told her story to the FBI on Jan. 24, 2017 when she was interviewed as part of Porter’s security clearance investigation. She also gave the photos to the FBI.

Holderness described Porter as having a “bad temper” – and an “angry person.”

Both of his ex-wives detailed physical and verbal abuse in prior press reports.

rob porter

Rob Porter was a key figure in Trump's White House. (AP)

During the White House briefing on Wednesday, Press Secretary Sarah Sanders said Porter had been “effective in his role” and the president had “confidence in his performance.”

Sanders initially said that Porter would not leave immediately.

Porter, meanwhile, pushed back strongly on the allegations in the press.

"These outrageous allegations are simply false. I took the photos given to the media nearly 15 years ago and the reality behind them is nowhere close to what is being described. I have been transparent and truthful about these vile claims, but I will not further engage publicly with a coordinated smear campaign,” Porter said in a statement provided by the White House.

“My commitment to public service speaks for itself. I have always put duty to country first and treated others with respect. I am deeply grateful for the opportunity to have served in the Trump Administration and will seek to ensure a smooth transition when I leave the White House.”

Holderness told Fox News it’s true that Porter took one photo of her – but that she asked him to, so she’d have evidence in case it happened again. Further, she said she took several of the other photos showing her bruise.

DailyMail.com recently reported that Porter had been dating White House Communications Director Hope Hicks, which Fox News has confirmed. Fox News also has learned that Hicks was involved in drafting the initial response to the first DailyMail.com report.

As staff secretary, Porter was a senior aide in Trump’s White House working in large part to manage the documents crossing the president’s desk.

Fox News' Judson Berger contributed to this report.