FBI Deputy Director Andrew McCabe is expected to retire from the FBI by March, CBS News has confirmed.

McCabe has come under considerable scrutiny from Republicans recently, as special counsel Robert Mueller's investigation into Russian election meddling and any ties to Trump associates marches forward. McCabe took temporary charge of the FBI after President Trump fired FBI Director James Comey earlier this year, and some skeptics have viewed McCabe as too close to his former boss.

President Trump tweeted about McCabe and Comey shortly after The Washington Post, which first reported his expected retirement, ran its story.

How can FBI Deputy Director Andrew McCabe, the man in charge, along with leakin’ James Comey, of the Phony Hillary Clinton investigation (including her 33,000 illegally deleted emails) be given $700,000 for wife’s campaign by Clinton Puppets during investigation? — Donald J. Trump (@realDonaldTrump) December 23, 2017

FBI Deputy Director Andrew McCabe is racing the clock to retire with full benefits. 90 days to go?!!! — Donald J. Trump (@realDonaldTrump) December 23, 2017

FBI Deputy Director Andrew McCabe is racing the clock to retire with full benefits. 90 days to go?!!! — Donald J. Trump (@realDonaldTrump) December 23, 2017

Republicans have long been skeptical of McCabe, who was connected to the FBI Clinton email investigation, because of his wife's ties to Democratic politics. McCabe's wife, Jill McCabe, received $500,000 in donations in 2015 from Virginia Gov. Terry McAuliffe, a close ally of the Clintons, in her bid for statewide office. Republicans asked why McCabe didn't remove himself from the Clinton email probe, perceiving a conflict of interest. McCabe's wife's campaign ended months before he become involved with the investigation, according to the FBI.

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Some of that skepticism intensified when Republicans learned earlier this month that Mueller removed former FBI agent Peter Strzok from his team over allegations that Strzok exchanged anti-Trump texts with another now-former member of Mueller's team, Lisa Page. Strzok was also key in the Clinton email investigation, which McCabe was a part of leading up to the 2016 presidential election.

Sen. Chuck Grassley, the Republican chairman of the Senate Judiciary Committee, has called for McCabe's removal.

McCabe, 49, first joined the FBI in 1996, and will be eligible for retirement benefits next year.

This is a developing story and will be updated.

CBS News' Andres Triay and Len Tepper contributed to this report.