WBC welterweight champion Robert Guerrero was arrested Thursday at Kennedy Airport for allegedly trying to bring a gun onto a plane.
Officials say the California native presented a lock box to a ticket agent with an unloaded .40-caliber handgun and three unloaded magazines inside.
He was arraigned on charges, including criminal possession of a firearm, and released on his own recognizance.
The 30-year-old Guerrero was set to defend his WBC welterweight title against Floyd Mayweather Jr. on May 4 in Las Vegas.
Guerrero is due back in court May 14.
Representatives for the boxer said he is legally allowed to have the firearm in his home state, but prosecutors said he should have checked New York's strict gun laws before bringing the weapon into the state.