Louisiana's attorney general says he plans no further investigation into the death of a chimpanzee at a New Iberia research center.

The Advertiser of Lafayette reports that Buddy Caldwell made his decision known in a letter to the Physicians Committee for Responsible Medicine.

That group had asked for an investigation into the 2011 death of an 8-year-old research chimp. The animal had become ill while being transferred from a Maryland facility to the University of Louisiana at Lafayette's research center in New Iberia.

The physicians committee had asked the attorney general's office to investigate the transport company, Stone Oak Farms and Transport in Opelousas.

Caldwell's April 19 letter said there is no evidence to prove a violation of animal cruelty laws.