Frank Carone, a Brooklyn power broker and longtime close associate of former Mayor Eric Adams of New York, was arrested on federal corruption charges on Wednesday along with his brother and a Queens developer, according to four people with knowledge of the matter.

F.B.I. agents took Mr. Carone, his brother Anthony Carone and the developer into custody at their homes in the early hours of Wednesday morning, one of the people said. A fourth person was also arrested as a result of the investigation, which began in early 2024.

Russell Capone, a lawyer for Frank Carone, and Katya Jestin, a lawyer for Anthony Carone, said they would not comment until after the charges are unsealed. It was not immediately clear who represents the other two defendants, Yan Po Zhu, known as Andy Zhu, and Crystal Chen.

Representatives of the F.B.I. and the office of the U.S. attorney for the Eastern District of New York, Joseph Nocella Jr., declined to comment.

Frank Carone, 56, a lawyer and consultant, was a powerful force in Brooklyn politics as counsel to the local Democratic Party. He became a political mentor to Mr. Adams, aiding his rise from state senator to Brooklyn borough president and ultimately to City Hall, where Mr. Carone served as the mayor’s chief of staff.

He held that job for only a year, leaving office to start a consulting firm that traded in part on his access to the former mayor. After Mr. Adams was himself indicted, Mr. Carone helped lead an ultimately successful effort to win the good graces of President Trump, whose Justice Department ultimately abandoned the federal corruption charges against Mr. Adams.

Like other of Mr. Adams’s former aides, Mr. Carone now faces legal jeopardy even as the former mayor moves on with his life.

Details about the specific accusations were unavailable Wednesday morning because the indictment remains sealed. But two of the people with knowledge of the matter said the case, brought by the U.S. attorney’s office in Brooklyn, involved a bribery scheme related to a migrant hotel in Long Island City owned by Mr. Zhu. Ms. Chen works for him.

Earlier this year, when the investigation was first disclosed, Mr. Carone released a statement denying wrongdoing.

He ascribed any scrutiny of his conduct to his political associations, jealousy over his success and “stereotypical assumptions” based on his Italian American roots and Brooklyn upbringing. “Baseless accusations are nothing new to me,” he said at the time.

A spokesman for Mr. Adams issued a statement Wednesday morning defending the former mayor’s chief of staff.

“Frank Carone has dedicated decades of his life to public service, the legal profession, and helping countless individuals, businesses and charitable organizations throughout New York,” the spokesman, Todd Shapiro, said in the statement. “This is an ongoing legal matter, and my prayers are with his family.”

The defendants were expected to appear in federal court in Brooklyn later Wednesday, after the indictment is unsealed.

This is a developing story. Check back for updates.