• A federal judge appointed a special watchdog to review material recently seized from Rudy Giuliani as part of a criminal probe of the former New York City mayor and personal lawyer for Donald Trump.
• The watchdog, attorney Barbara Jones, will recommend what electronic files of Giuliani's can be seen by prosecutors, and what material should be exempt as evidence because it is protected by attorney-client privilege.
• Jones served in the same capacity as a so-called special master during the federal criminal investigation of Michael Cohen, who had been Trump's personal lawyer for more than a decade.

A federal judge on Friday appointed a special watchdog to review material recently seized from Rudy Giuliani as part of a criminal probe of the former New York City mayor, who has served as a personal lawyer for ex-President Donald Trump.

The watchdog, former federal Judge Barbara Jones, will recommend what electronic files of Giuliani's can be seen by prosecutors, and what material should be exempt as evidence because it is protected by attorney-client privilege.

Jones three years ago served in the same capacity as a so-called special master during the federal criminal investigation of Michael Cohen, who had been Trump's personal lawyer for more than a decade before they had a falling out. Cohen later pleaded guilty in that case to multiple crimes and served more than a year in prison.

Giuliani is under criminal investigation for dealings in Ukraine, which include work done while he was acting as Trump's lawyer.

Jones, who is a partner in the Bracewell firm, also will review electronic files recently seized from another Trump allied lawyer, Victoria Toensing, as part of the criminal probe of Giuliani.

The files of both lawyers were seized through search warrants.

Prosecutors had asked Manhattan federal Judge J. Paul Oetken on Thursday to appoint Jones as special master, and in a court filing told the judge that attorneys for Giuliani and Toensing supported that request.

"Judge Jones's reputation for integrity and fairness made her the unanimous choice for all parties," Giuliani's lawyer, Arthur Aidala, told CNBC. "We look forward to working with her."

Cohen, in a text message to CNBC, said, "Judge Jones was professional in the review and determination of attorney/client privilege of the more than 10 million documents in my case."

"The choice of Judge Jones and the expeditious manner to which she conducts her court will not inure to the benefit of Rudy," Cohen wrote.

In their request for Jones' appointment, prosecutors noted that Giuliani previously had been a shareholder in the Bracewell firm, "which was then known as Bracewell & Giuliani."

"In January 2016, Mr. Giuliani left the firm, and Judge Jones did not join the firm until July 2016," prosecutors wrote. "None of the parties believe that Mr. Giuliani's prior affiliation with Bracewell & Giuliani presents a conflict that would disqualify Judge Jones from being appointed as a special master or her firm assisting in her review."

Prosecutors also told Oetken that another partner at Bracewell who had helped Jones in reviewing Cohen's files for privileged material, and "who has a personal relationship with Mr. Giuliani, will recuse himself from this matter in order to avoid the appearance of any conflict."

Giuliani is under investigation by the U.S. Attorney's Office for the Southern District of New York.

That office, which Giuliani once headed, in particular is eyeing whether he violated a law requiring people to register as agents representing the interests of foreign powers in certain cases. Giuliani during Trump's presidency had pursued information about President Joe Biden and his son Hunter Biden among other things.

Giuliani had said he did nothing illegal.

Trump himself is under criminal investigation by the Manhattan district attorney's office.