Federal prosecutors say an Omaha woman who used spas as fronts for prostitution has been sentenced to prison.

U.S. District Judge Laurie Smith Camp sentenced 46-year-old Kimberly Bivens on Wednesday to more than three years in federal prison, followed by three years of supervised release.

Bivens pleaded guilty to an interstate prostitution conspiracy charge.

Bivens operated three Omaha spas from 2009 to 2011 and placed ads on the Internet. An FBI and Omaha Police Department investigation found 20 workers were performing sex acts for paying customers.

Authorities say the operation attracted people from Nebraska, Iowa and other states.