(Bloomberg) -- Lawyers for Hunter Biden, President Joe Biden’s son, asked federal and state prosecutors to investigate people he accused of accessing and disseminating personal data, and also threatened Fox News host Tucker Carlson with a defamation suit. 

The requests, made in a series of criminal referrals and cease-and-desist letters, show Hunter Biden is adopting a more aggressive strategy against attacks and accusations from prominent conservatives and Republicans that are at the heart of the House GOP’s plan to investigate the president and his son.

Abbe Lowell, a lawyer for the younger Biden, wrote lengthy letters to the Justice Department and the Delaware attorney general requesting criminal inquiries into allies of former President Donald Trump, including former New York City Mayor Rudy Giuliani and former Trump strategist Steve Bannon, who were involved in spreading data from a laptop Hunter Biden is said to have left at a Delaware repair shop in 2019.

“The actions described above more than merit a full investigation and, depending on the resulting facts, may merit prosecution under various statues,” Lowell wrote to the Justice Department. “It is not a common thing for a private person and his counsel to seek someone else being investigated, but the actions and motives here require it.” 

The Justice Department, which is also investigating Hunter Biden for tax evasion, is under no obligation to take action on the requests. The department declined to comment on Wednesday night.

The Washington Post and ABC News reported earlier on the letters.  

Read More: Republicans to Launch Biden Probe Hours After State of the Union

Another lawyer for Hunter Biden, Bryan Sullivan, wrote to Carlson and Fox News demanding retractions of statements made about the president’s son on his program, including that he had access to classified documents found at the president’s Wilmington, Delaware, home. 

Representatives for Fox News did not immediately respond to requests for comment.

The laptop came to the public’s attention toward the end of the 2020 presidential campaign when the New York Post reported on emails it said were found on the laptop computer related to the younger Biden’s overseas business dealings. Trump used the report against Joe Biden in the final days of his failed run for a second term. 

The president has denied knowledge of his son’s business dealings and his son has disputed the authenticity of material said to be from the laptop.

The House Oversight Committee has scheduled a Feb. 8 hearing that is expected to focus on the laptop and Twitter Inc.’s efforts to limit access to the article about its purported contents. The hearing will be held the day after Biden delivers his State of the Union address at the Capitol. 

A committee spokeswoman, Jessica Collins, said the panel did not receive word of the letters from Biden’s lawyers.  

In addition to Bannon and Giuliani, Lowell is also seeking an investigation into Giuliani attorney Robert Costello and the owner of the computer repair shop, John Paul Mac Isaac, who said Biden dropped off the computer but never picked it up. 

The letter said Mac Isaac admitted in his recently-published book, “American Injustice,” to reviewing “sensitive, private material” on the laptop, including a file titled “income.pdf.” He then passed a copy of the laptop to Costello, who shared it with Giuliani, who was acting as a personal lawyer to Trump in his effort to overturn the results of the 2020 election.

“The two letters constitute a frivolous legal complaint trying to intimidate. The letters reek of desperation because they realize that Judgment Day is coming for the Bidens,” Costello said in response to the letter. He added that a work order signed by Hunter Biden allowed Mac Isaac to examine the laptop, and the hard drive became his property after it was abandoned at his shop.

“After skimming the letters, the only thing I see is a privileged person hiring yet another high-priced attorney to redirect attention away from his own unlawful actions,” said Brian Della Rocca, a lawyer representing Mac Isaac.

The letter also accuses Giuliani of giving the laptop to Bannon, who helped deliver its contents to news media outlets.

Ted Goodman, a spokesman for Giuliani who called the letters an “obvious attempt” to silence the former mayor. “Raising concerns now, after so many years, indicates just how devastating the texts and videos from Hunter’s laptop truly are,” he said. 

--With assistance from Billy House, Chris Strohm and Zoe Tillman.

©2023 Bloomberg L.P.