As federal prosecutors scrutinize Mayor Eric Adams and his top aides, the Manhattan district attorney’s office has opened yet another corruption investigation into City Hall, this one involving the city’s leasing of commercial properties, people with knowledge of the matter said.

As part of the inquiry, investigators have seized the phones of at least five people — including Mr. Adams’s chief adviser, a top New York City real estate official and a broker involved in city leases, the people said. The investigation has focused at least in part on possible bribery, money laundering and other crimes, one of the people said.

Details of the district attorney’s inquiry have not been previously reported. It brings to five the number of corruption inquiries surrounding the mayor of America’s largest city and represents still another area of scrutiny for the many law enforcement agencies examining Mr. Adams and his top aides.

The phones and other electronic devices were seized on Sept. 27 at Kennedy Airport as the mayor’s chief adviser, Ingrid Lewis-Martin, returned from a vacation in Japan with a group of friends. That group included the city real estate official, Jesse Hamilton; the broker, Diana Boutross and others, the people said.

As the district attorney’s investigators seized electronic devices, they also notified Ms. Lewis-Martin that they were simultaneously searching her home in Brooklyn. At about the same time, a different set of investigators from the U.S. attorney’s office in Manhattan, which brought an indictment against the mayor late last month, served Ms. Lewis-Martin with a grand jury subpoena seeking documents in that case.