Joseph DiGenova, a conservative attorney who previously represented President Trump's campaign when it challenged the results of the 2020 election, is being tapped by the U.S. Justice Department to lead an ongoing criminal investigation into former CIA Director John Brennan, a Justice Department official said on Saturday.

DiGenova, who will oversee the probe from the Southern District of Florida, is joining the team just days after Maria Medetis Long was removed from the case, CBS News previously reported. He will serve as counselor to acting Attorney General Todd Blanche, the official added.

A source familiar with the matter told CBS News that Medetis Long was taken off the case after expressing concerns about the strength of the evidence. A Justice Department spokesperson on Friday said changing up personnel on cases was "healthy and normal" without elaborating on the reasons for the change.

The decision to add DiGenova and remove a career federal prosecutor from the probe is likely to stoke concerns about whether the case is politically motivated. The personnel switch has echoes of another case last year when Mr. Trump ousted the top federal prosecutor in Virginia's Eastern District and replaced him with a loyalist after he expressed concerns about the strength of the evidence in cases against former FBI Director James Comey and New York Attorney General Letitia James.

Charges against James were later dismissed, although a Trump administration official made new criminal referrals last month to federal prosecutors in Miami and Chicago for two cases of possible homeowner's insurance fraud. 

DiGenova is a staunch Trump ally who repeatedly pushed conspiracy theories alleging the 2020 election was stolen. In 2021, he was forced to apologize to Chris Krebs, the former director of the Cybersecurity and Infrastructure Agency who was fired during Mr. Trump's first term, after Krebs said he felt the 2020 election was free of major fraud or interference. 

Krebs later sued DiGenova after he called for Krebs to be "drawn and quartered" and "shot" during a television appearance. Those comments, Krebs later alleged, sparked death threats against him. 

DiGenova, 81, previously served as U.S. attorney in Washington, D.C., under Republican President Ronald Reagan.

The probe into Brennan was sparked by a referral from the Republican-led House Judiciary Committee last October over allegations that Brennan lied to Congress about the CIA's role in crafting the intelligence assessment into Russia's efforts to meddle in the 2016 presidential election.

In the referral, Chairman Jim Jordan claimed Brennan "falsely" denied the CIA relied on a dossier prepared by former British intelligence officer Christopher Steele during the drafting of the intelligence assessment and falsely told the committee the CIA had opposed including the Steele dossier in the assessment.

The so-called Steele dossier contained salacious allegations against then-candidate Trump that have not been verified.

The case has been heating up in recent weeks, as members of the team continue to conduct interviews with key witnesses. Chris DeLorenz, a former law clerk to U.S. District Judge Aileen Cannon during special counsel Jack Smith's probe into Mr. Trump's retention of classified records, is also involved in the case after he recently left his role in the deputy attorney general's office to become a prosecutor in the Southern District of Florida.

In:

• Chris Krebs
• John Brennan
• Donald Trump