The mayor of Jackson, Miss., a City Council member and the local district attorney have been indicted on federal corruption charges, with court documents unsealed on Thursday detailing a scheme in which F.B.I. agents posing as real estate developers paid tens of thousands of dollars in bribes to city officials.

Mayor Chokwe Antar Lumumba, a Democrat first elected to lead the state’s capital in 2017, and the City Council member, Aaron Banks, were indicted on conspiracy and bribery charges. The Hinds County district attorney, Jody Owens, faces similar charges and was also accused of making false statements. All three men pleaded not guilty on Thursday in their first court appearances.

In the 32-page indictment, prosecutors said that beginning last year, F.B.I. agents assumed the guise of out-of-state developers eager to build a hotel on a long-vacant piece of prime property in downtown Jackson. Working with Mr. Owens as a kind of fixer, the developers offered money to Mr. Lumumba and two City Council members in exchange for their support for the developers’ plans, the indictment says.

It also accuses Mr. Lumumba of accepting $50,000 in campaign contributions as a bribe. Mr. Banks is accused of requesting $50,000, a security detail and a job for a family member in exchange for his support.

Angelique Lee, a former City Council member, resigned her position this year and pleaded guilty to a charge of conspiracy to commit bribery.

The scandal is a blow to the city of 150,000, whose mostly Black residents have struggled in recent years to obtain even basic city services. In 2022, the city’s water system essentially collapsed, leaving homes, businesses, schools and medical facilities with little to no water pressure for days. Last year, residents’ garbage piled up for two weeks as the mayor and City Council feuded over who should get the contract.