An adviser to Special Counsel Robert Mueller is reportedly tasked with researching every legal precedent and limitation to the power of a presidential pardon, as the Justice Department probes Russian interference in the election and possible links between Moscow and President Trump's campaign.

Michael Dreeben, the top legal counsel to Mueller's chief investigator, is delving into the history of presidential pardons, whether any restrictions could apply to them, and various interpretations of the law, Bloomberg reported Tuesday.

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The news outlet, citing an unidentified source, reported that Mueller is laying the groundwork for the possibility that Trump pardons his aides or allies before prosecutors can charge anyone within his inner circle.

Dreeben is also working to ensure that every step Mueller's team makes will hold up in court against an appeal, according to Bloomberg, which pointed to the search warrant and raid of Paul Manafort’s Virginia home in late July. Manafort served as Trump's campaign manager.

Dreeben has appeared before the Supreme Court more 100 times during his career as a government lawyer, Bloomberg noted.

"He’s seen every criminal case of any consequence in the last 20 years," lawyer Kathryn Ruemmler of Latham & Watkins LLP told the news outlet.

"If you wanted to do a no-knock warrant, he’d be a great guy to consult with to determine if you were exposing yourself," added Ruemmler, who served as White House counsel under former President Barack Obama Barack Hussein ObamaObama calls on Senate not to fill Ginsburg's vacancy until after election Senate Republicans face tough decision on replacing Ginsburg Cruz: Trump should nominate a Supreme Court justice next week MORE.

Mueller's investigation appears to be picking up steam as he asks the White House to turn over all its documents related to Russian activity and prepares to interview former and current aides to Trump.