Federal investigators are seeking communications among New York’s former police commissioner, his twin brother and officers that might show payments made in exchange for favors to nightclubs, according to a person with direct knowledge of the investigation.

The investigation is focused on cellphone records and communications involving the former commissioner, Edward A. Caban, and his brother James Caban dating back to Jan. 1, 2018, according to the person.

Investigators are looking for evidence that would support bribery, fraud and conspiracy charges, said the person, who, lacking authorization to discuss the case publicly, asked to speak anonymously. No one has been arrested or charged.

The person’s account gave a fuller picture of what investigators have been seeking as they have fanned out through the city, issuing search warrants and subpoenas to members of Mayor Eric Adams’s administration, which has been engulfed in at least four federal inquiries that have already led to several resignations.

Edward Caban, 57, was the first to resign on Sept. 12, at the request of City Hall, which had asked him to step aside after federal agents seized his phone on Sept. 4 as part of a criminal investigation.