Mayor Eric Adams of New York set up the fund amid a broad federal corruption investigation into his campaign’s fund-raising practices.Mayor Eric Adams raised $732,000 in less than two months to pay for legal expenses related to a federal investigation into his campaign fund-raising, according to a filing submitted Tuesday.The contributors to Mr. Adams’s defense fund include an array of wealthy players in business and politics, among them at least four who have been described as billionaires: the former New York City mayor Michael Bloomberg, the Ukrainian-British oligarch Leonard Blavatnik, the real estate and fertilizer tycoon Alexander Rovt and the cryptocurrency investor Brock Pierce.The fund has so far spent $440,000, most of it on WilmerHale, the law firm Mr. Adams hired to represent him in the investigation, the filing shows.City law permits elected officials to set up defense funds to pay for expenses related to criminal or civil investigations that are unrelated to their government duties and cannot be paid for with public money. The funds can collect up to $5,000 per donor but are not permitted to solicit or receive contributions from anyone with city contracts or business before the city.The Eric Adams Legal Defense Trust was set up late last year after the F.B.I. searched the home of Brianna Suggs, who was then Mr. Adams’s chief campaign fund-raiser. It made its first filing with the city’s Conflicts of Interest Board on Tuesday.Mr. Adams, who unveiled his preliminary city budget on Tuesday, said the support had come from donors who appreciated his “life of service,” from his time as a transit police officer to his tenure as mayor.“They said, ‘We want to help,’” he said. “People have known my character, and they said, ‘We want to help.’”The four billionaires and their relatives contributed a total of $40,000 to the fund. Mr. Pierce, a former child actor who is now a cryptocurrency investor, has previously supported the mayor. Mr. Adams has praised cryptocurrency, and he flew on Mr. Pierce’s private jet to Puerto Rico shortly after he was elected mayor. Since his campaign, Mr. Adams has also nurtured a relationship with Mr. Bloomberg, who left City Hall at the end of 2013.Frank Carone, Mr. Adams’s first chief of staff and a longtime adviser, and his relatives pitched in $20,000, while Lori Fensterman, the wife of Mr. Carone’s former law partner, gave $5,000. The mayor himself gave two donations totaling $120.Among the other donors were Jenifer Rajkumar, a state assemblywoman from Queens and a close ally of Mr. Adams, who gave $2,500; Angelo Acquista, a pulmonologist and diet book author, and his wife, Svetlana Acquista, who gave Mr. Adams a total of $10,000; and Michael Cayre, an owner of Casa Cipriani who, with two family members, donated $15,000. Mr. Cayre recently organized a gala at the club that reportedly raised about $10 million for victims of the Oct. 7 Hamas attacks, with Mr. Adams in attendance. The bulk of the fund’s expenses so far, about $397,000, was paid to WilmerHale, where Mr. Adams’s defense team includes Brendan McGuire and Boyd Johnson, two former top prosecutors at the Southern District of New York, which is conducting the investigation along with the F.B.I. Mr. McGuire also formerly worked as Mr. Adams’s chief counsel in City Hall.The fund also paid $7,500 to Pitta L.L.P., a law firm whose co-managing partner, Vito Pitta, is overseeing the fund. It paid about $25,000 to two companies for “vetting and investigative services” and “forensic data collection.”The City Council authorized legal defense funds in 2019 after the Conflicts of Interest Board ruled that city gift restrictions prohibited Mr. Adams’s predecessor, Bill de Blasio, from soliciting more than $50 per donor to pay for legal bills he had accumulated during state and federal investigations into his fund-raising.The investigation into Mayor Adams’s fund-raising came into view in early November. On the same day as the search of Ms. Suggs’ home, F.B.I. agents also searched the New Jersey houses of Rana Abbasova, an aide in Mr. Adams’s international affairs office, and Cenk Ocal, a former Turkish Airlines executive who served on his transition team. A few days later, agents stopped Mr. Adams after a public event and seized several electronic devices from the mayor.Federal officials in Manhattan are examining whether the Turkish government conspired with Mr. Adams’s campaign to funnel donations into campaign coffers and whether Mr. Adams pressured Fire Department officials to sign off on a new high-rise Turkish consulate despite safety concerns.Neither Mr. Adams nor anyone else connected to the investigation has been accused of wrongdoing. The mayor and his representatives have said that he has followed the law scrupulously.On Tuesday, new campaign fund-raising disclosures for the 2025 mayor’s race also became public — the first such filings since the federal investigation into the Adams campaign came to light. They showed that Mr. Adams’s campaign raised $524,800 since July — a significantly lower figure than in the first half of 2023, when he raised $1.3 million.The mayor’s campaign received nearly 600 donations from lawyers and real estate leaders, but only about two dozen of the donations came after the Nov. 2 raid on the fund-raiser’s home. More