The San Diego County Medical Examiner's Office is limited to looking for manner and cause of death, said Sarah Gordon, a spokeswoman for the agency.

"If the family makes requests for outside research, we will participate, with family consent," she said. At this point, the family has not made any such request, she said.

Seau apparently died after shooting himself in the chest.

(Reporting by Marty Graham: Writing by Alex Dobuzinskis)