Six police officers who work for a Northwest Indiana sheriff’s department have suspended and are now under federal investigation for possible gun violations. The officers work for the sheriff’s department in Lake County, Indiana. The sheriff there, John Buncich, suspended the officers and stripped them of their police powers earlier this week.

An investigation by federal authorities is now underway. It reportedly centers on the sale of guns across state lines.

“I put them under administrative leave, which is the most I could do right now under Indiana law until any charges are formally filed,” Buncich told WBEZ on Thursday. “They have been stripped of all their law enforcement authority until that time.”

Three of the suspended officers held top department positions under Buncich’s predecessor, Roy Dominguez, whose term ended in December. One of them is Marco Kuyachich, who served as police chief under Dominguez and was a candidate for county sheriff last year. Buncich said when he took office, he did a complete inventory of all department equipment.

“There were some things that just weren’t proper in my mind or weren’t in place and I contacted the authorities,” Buncich said.

Buncich said some of the agencies that have visited the department as part of the investigation include the Federal Bureau of Investigation, Bureau of Alcohol, Tobacco and Firearms, Internal Revenue Service, U.S. Food and Drug Administration and the U.S. Department of Defense.

So far, no charges have been filed.