NASHVILLE (AP) - A trial has begun over how Nashville's five jail facilities pay hundreds of correctional officers.

More than 850 current and past Davidson County Sheriff's Office corrections officers are suing Metro Nashville government over $7 million in back wages they say they are owed, dating back to 2006, The Tennessean (http://tnne.ws/1KPXWBw ) reported.

Attorney David Garrison, of Nashville firm Barrett Johnson Martin & Garrison, told a jury in U.S. District Court that the officers are paid "at lower hourly rates than it tells them that they are getting paid." The firm represents the employees in a class-action suit.

"The Metro government pays its correctional officers at lower hourly rates than it tells the public it pays them. That's what the case is about. It's very simple," Garrison said.

The employees say they earn hourly wages but that the government pays them by dividing an annual salary by their hours worked. Because that is over 40 hours each week, the employees say they are paid less than the hourly wage listed in the city's pay plan.

Assistant Metro Attorney Chris Lackey said new hires are told they are paid based on an annual salary. He said in an opening statement that no attempt was made to dupe employees.

If the jury decides Metro government benefited or was "unjustly enriched" because of the pay plan, a federal judge will decide how much restitution the city should pay.