POCATELLO, Idaho (AP) -- Federal prosecutors say a southern Idaho feedlot manager convicted of violating drinking water laws was actually pumping contaminated wastewater in the aquifer below his operation.

Cory King, co-owner of Double C Farms near Burley, was convicted in April on four counts of injecting fluids into the aquifer without a permit and one count of making a false statement to investigators. King is scheduled to be sentenced next month.

But on Monday, U.S. District Judge B. Lynn Winmill presided over an evidentiary hearing in the case.

During his trial, the Times News reports the judge barred any evidence related to the exact contents of the fluids injected into the aquifer.

But prosecutors contend now those fluids were wastewater that tested positive for E. coli bacteria.

Defense attorneys say tests on the fluids were flawed.