Several federal corruption investigations have reached people in the orbit of Mayor Eric Adams of New York, with Mr. Adams, who faces re-election in 2025, and some of the highest-ranking officials in his administration coming under scrutiny.

Here are people with ties to Mr. Adams that are related to the investigations and other legal issues:

Officials with the U.S. attorney’s office for the Southern District of New York in Manhattan, which is conducting three of four federal investigations, have declined to answer questions about the scope, and their full scope is unclear.

Neither the mayor nor others from whom information has been sought have been charged with a crime, and it is possible some of those targeted for searches are only witnesses. The city’s Department of Investigation is involved in the four inquiries.

Federal inquiry into Adams, his campaign and ties to Turkey

This investigation, by federal prosecutors in Manhattan, appears to be focused in part on whether the Adams 2021 campaign conspired with the Turkish government to receive illegal foreign donations, and whether Mr. Adams pressured the Fire Department to approve a new high-rise Turkish consulate, despite safety concerns.

Last November, F.B.I. agents stopped Mr. Adams outside an event and seized his electronic devices. In July, prosecutors served a new round of grand jury subpoenas to Mr. Adams, his office and his campaign.

The Brooklyn home of Brianna Suggs, Mr. Adams’s chief fund-raiser at the time, was searched by federal agents in November. Weeks later, he said she would leave the role.

Federal agents also searched the New Jersey homes of Rana Abbasova, an aide in the mayor’s international affairs office and a former liaison to the Turkish community for Mr. Adams, and Cenk Öcal, a former Turkish Airlines executive who served on the mayor’s transition team. Ms. Abbasova is cooperating with the investigation.

Federal inquiry into ex-police commissioner’s twin brother

At the request of City Hall, Edward A. Caban resigned as police commissioner last week, just days after federal agents seized his phone and that of Raul Pintos, who served as chief of staff under Mr. Caban, and the commanders of two Queens precincts. Mr. Pintos is scheduled to retire in October.

This investigation, by federal prosecutors in Manhattan, appears to be focused on a nightclub-security business owned by Mr. Caban’s twin brother, James Caban. A former police officer who was fired in 2001, James Caban also had his phone seized. Lawyers for Edward Caban have said prosecutors told them he was not a target of the investigation.

Federal inquiry into senior City Hall aides and associates

This investigation, by federal prosecutors in Manhattan, appears to center on a possible bribery scheme involving a government-relations consulting company run by Terence Banks, a brother of Philip Banks III, the deputy mayor for public safety, and of David C. Banks, the schools chancellor. Terence Banks also helped raise funds for Mr. Adams’s 2021 campaign and was on his transition committee.

The investigation, which appears to be in the early stages, appears to be focused at least partly on city contracts issued under programs geared toward small companies owned by women and members of minority groups.

This month, federal agents seized the phones of several top City Hall aides: the first deputy mayor, Sheena Wright; David Banks, her partner; and Philip Banks. Investigators also sought information from Timothy Pearson, a senior adviser and one of the mayor’s closest confidants.

A lawyer for Terence Banks said he and his client had been “assured by the government” Mr. Banks was not the target of the investigation. A lawyer for Philip Banks said his client had done nothing wrong. David Banks said he was cooperating with a federal inquiry, and that his lawyer had been informed Mr. Banks was “absolutely not a target in whatever this investigation is about.”

Other investigations and legal matters

The fourth federal investigation, run by the U.S. attorney’s office for the Eastern District of New York in Brooklyn, led to a search in February of homes owned by Winnie Greco, a close aide to Mr. Adams who was then his director of Asian affairs and a prominent campaign fund-raiser.

City officials said at the time Ms. Greco would be placed on unpaid leave during the inquiry, but the website The City reported in May she had returned to a government job. The prosecutors’ office declined to answer questions.

Last year, Eric Ulrich, a one-time Department of Buildings commissioner appointed to the post by Mr. Adams, was indicted by a Manhattan grand jury on 16 felonies, including conspiracy and taking bribes. He had previously resigned after news of the investigation became public. According to court records, Mr. Ulrich has pleaded not guilty.

In February, a retired police inspector, Dwayne Montgomery, pleaded guilty to misdemeanor state charges in Manhattan, admitting that he had directed so-called straw donors — people who make campaign donations with someone else’s money — to contribute to the mayor’s 2021 campaign.

Mr. Pearson also faces several lawsuits involving sexual harassment accusations. A lawyer representing him denied wrongdoing on his behalf. In recent days, two security guards, whom Mr. Pearson was seen physically attacking at a Midtown migrant shelter last fall, said that they planned to sue him and the city for false arrest and malicious prosecution. A lawyer representing him had not responded for comment.