Trump's personal lawyer Rudy Giuliani speaks during a press conference at the Republican National Committee headquarters in Washington, DC, on November 19, 2020.
CNN  — 

Federal prosecutors investigating Rudy Giuliani’s activities in Ukraine have closed their investigation after more than two years and said no criminal charges will be brought.

Prosecutors with the office of US Attorney for the Southern District of New York have been investigating Giuliani, the former personal attorney to former President Donald Trump, for possible violations of foreign lobbying laws since early 2019.

On Monday, they informed a judge overseeing the investigation that they were closing the case.

The notification came in a court filing with prosecutors asking the judge to terminate the special master who was appointed to oversee a review of documents obtained when the FBI executed a search warrant on the former New York City mayor’s home in April 2021.

“The Government writes to notify the Court that the grand jury investigation that led to the issuance of the above-referenced warrants has concluded, and that based on information currently available to the Government, criminal charges are not forthcoming,” prosecutors wrote.

A spokesman for the US attorney’s office declined to comment.

“It’s wonderful, long-expected news,” said Robert Costello, an attorney for Giuliani. “Unfortunately, Mayor Giuliani had to spend two and a half years to three years with this cloud over his head.”

Ted Goodman, a spokesperson and political adviser to Giuliani, said: “The mayor has been completely and totally vindicated. We hope this will help bring an end to the unwarranted attacks on the mayor - a man who is quite literally the most successful prosecutor of the most dangerous criminals over the past fifty years. I challenge someone to find a more successful crime fighter than Rudy Giuliani, a man who cleaned up city government and took down the mafia.”

The end of the investigation also closes a chapter from the Trump administration that involved two South Florida businessmen, shadow diplomacy efforts including a plot to oust the US ambassador to Ukraine, and an impeachment trial of the former president.

Prosecutors had examined whether Giuliani violated foreign lobbying laws by operating on behalf of Ukrainian officials when he sought the ouster of the then-US ambassador to Ukraine, Marie Yovanovitch, while urging Ukraine to investigate Trump’s 2020 political rival, then-Democratic presidential candidate Joe Biden, and his son Hunter.

US law requires anyone lobbying on behalf of a foreign government or official to register and failing to do so is a violation.

Giuliani had claimed his activities in Ukraine were done in his capacity as a lawyer for Trump, and that he “never represented a Ukrainian national or official before the United States government.”

In April 2021, federal agents executed search warrants at Giuliani’s Manhattan apartment and Park Avenue office, seizing 18 electronic devices. Prosecutors also disclosed that they had covertly searched Giuliani’s iCloud account in 2019. Earlier this year he met with prosecutors and provided passwords for some of the locked devices.

The green light for the search warrants – especially against a former president’s personal attorney – was one of the first high-profile moves by Attorney General Merrick Garland in the early days of the Biden administration.

Giuliani’s role as the then-president’s attorney and his involvement with Ukrainian officials added complexity to the investigation, people familiar with the matter told CNN. It wasn’t clear if Giuliani received any compensation from Ukrainians and he was publicly touting his efforts, which could make it more difficult for prosecutors to prove he was secretly lobbying for foreign actors.

Two South Florida businessman, Lev Parnas and Igor Fruman, helped introduce Giuliani to Ukrainians and translate for him on trips. Once viewed as potential witnesses in the government’s case, they became caught up in their own campaign finance and fraud scheme and have both been found guilty or pleaded guilty.

The decision to close the investigation also shows the challenges the Justice Department has faced when trying to enforce foreign lobbying laws, an area of increased focus because of the potential risks to national security.

Earlier this month, Trump ally Tom Barrack and his former assistant were acquitted of acting as undisclosed foreign agents for the United Arab Emirates.

The New York investigation isn’t the only legal threat Giuliani is facing. His actions trying to overturn the 2020 election results to favor Trump have drawn scrutiny and potentially costly fines or settlements. Dominion Voting Systems filed a billion-dollar defamation lawsuit against Giuliani for his unfounded election fraud claims.

Giuliani has been told he’s a target of the criminal investigation conducted by the special grand jury in Fulton County, Georgia, which is investigating Trump’s efforts to sway the election in his favor. He appeared before the grand jury in August.

Federal prosecutors are also conducting a wide-ranging investigation into efforts to interfere with the transfer of power from the Trump to Biden administration.

This story has been updated with additional details.