Federal prosecutors have asked a judge to appoint an outside lawyer to review the records seized from Rudolph W. Giuliani — echoing the Justice Department’s pursuit of a criminal case against a previous attorney for former president Donald Trump, Michael Cohen.

In a letter unsealed Tuesday, federal prosecutors in Manhattan asked U.S. District Judge J. Paul Oetken to appoint what’s known as a special master to examine evidence taken late last month from the former New York mayor’s home and office. They cited the Cohen case as a past example when such an appointment helped to show that Trump’s lawyer was treated fairly.

FBI agents seized cellphones and other electronic devices from Giuliani, as well as the cellphone of D.C.-area lawyer Victoria Toensing, as part of an investigation to determine whether Giuliani acted as an unregistered agent of foreign interests. Giuliani, who worked as a lawyer for Trump in 2019 and 2020, the time frame under investigation, has not been charged and has denied any wrongdoing.

Andrew Giuliani, son of former New York mayor Rudolph W. Giuliani, on April 28 expressed outrage over federal agents’ search of his father’s Manhattan home. (The Washington Post)

It is not that unusual for authorities in a case involving lawyers’ records to use a “filter” or “taint” team to review seized material and decide what information is relevant to the warrant and keep separate any information that is covered by attorney-client privilege.

It is unusual, however, for prosecutors to preemptively ask for an outside special master to oversee such work and make determinations. In the Cohen case, his defense attorneys requested such an appointment, and the judge agreed.

In the Giuliani case, prosecutors explained to the judge that “the unusually sensitive privilege issues that the Warrants may implicate” make a court-appointed special master appropriate.

Citing a legal conclusion reached by the judge in Cohen’s case, prosecutors said a filter review inside the Justice Department would be fair, but in such a high-profile case like Giuliani’s it was important to provide not just fairness, but “the perception of fairness.”

In Cohen’s case, a respected former federal judge was appointed special master, and after the evidence was reviewed and turned over to the investigative team, Cohen decided to plead guilty and was sent to prison.

The letter unsealed Tuesday also states that after the searches were executed April 28, “specialists with the FBI have begun to extract materials from the seized devices, but the review of those materials has not begun.”

Since the seizure of his devices, Giuliani has expanded his legal team as he tries to fight the case.

The investigation by the U.S. attorney’s office in Manhattan is focused on Giuliani’s interactions with Ukrainian figures at the time he was serving as Trump’s lawyer. Ahead of last year’s presidential election, Giuliani sought information that might prove politically damaging to then-candidate Joe Biden and pressed for the ouster of the U.S. ambassador to Ukraine. The episode factored prominently in Trump’s first impeachment, but Justice Department leaders had resisted approving a search warrant late in his administration.

After the devices were seized, Robert Costello, one of Giuliani’s lawyers, issued a lengthy statement saying that although the Justice Department may have the former mayor’s phone and computer, it does not have a viable case against him.