Federal agents arrested the mayor of New Jersey's capital city early Monday as part of an ongoing corruption investigation into bribery allegations related to a parking garage project that was concocted as part of an FBI sting operation.

Trenton Mayor Tony Mack, his brother Ralphiel and convicted sex offender Joseph Giorgianni, a Mack supporter who owns a Trenton sandwich shop, were accused of conspiring to obstruct, delay and affect interstate commerce by extortion under color of official right.

Federal prosecutors alleged Mack agreed to use his influence in connection with a proposed parking garage project in the city. The garage was made up — a fake project created by investigators to try to capture Mack, who has financial problems and attracted legal scrutiny since he took office.

Federal agents began investigating Mack and the others in September 2010. Mack had become mayor in July.

The defendants received $54,000 and anticipated accepting another $65,000 from a cooperating witness who purported to be a developer, according to court documents that laid out the sting and the accusations of wrongdoing.