Animal welfare groups are pushing SeaWorld to release more information about how Tilikum, the orca that killed a trainer at the company's Orlando park, died from an infection in January.
SeaWorld announced earlier this month that a necropsy revealed the whale had died from bacterial pneumonia. But the Orlando Sentinel reports that groups want to know where the infection came from and if Tilikum had other injuries.
Tilikum was profiled in the documentary "Blackfish,'' which helped sway public opinion against keeping killer whales in captivity.
Details about deaths of whales and dolphins in captivity have been shielded from the public since 1994, when Congress amended the Marine Mammal Protection Act after industry lobbying.
SeaWorld officials say Tilikum's tissues are being used in studies that will be published when complete.