A federal grand jury returned a criminal indictment Friday against New Orleans Mayor LaToya Cantrell, accusing the mayor of pursuing an illicit affair with her police bodyguard on taxpayers’ dime, then lying to federal officials and deleting evidence to hide the relationship.

The indictment is the culmination of a long-running federal corruption investigation into Cantrell, the first female mayor in the city’s 300-year history.

Officials allege she defrauded the city while trying to keep hidden her relationship with a police officer assigned to protect her.