DES MOINES (AP) - State environmental officials want the Iowa attorney general to impose a larger-than-normal fine against a brother of former Iowa Gov. Terry Branstad for pollution violations.

Investigators say Monroe "Monty" Branstad of Forest City should be fined more than the maximum $10,000 for alleged pollution violations in the Winnebago River that officials claim killed 31,000 fish valued at $63,000.

Officials say the silage spill at Branstad's cattle farm in August ranked among the 40 deadliest for Iowa wildlife since 1995.

Kelli Book, a lawyer for the Iowa Department of Natural Resources, says the fine amount could be based on past problems, a prior fine remaining unpaid and the severity of the spill.

Branstad could be fined $100,000.

An attorney for Branstad, Jim Pray, says regulators have failed to prove the severity of the fish kill.