None of the six prescription drugs found in OU linebacker Austin Box’s system were prescribed to him, El Reno Police Chief Ken Brown said.

The police department checked the drugs against Oklahoma’s prescription-monitoring database, and none of the five pain-killers — oxymorphone, morphine, hydrocodone, hydromorphone and oxycodon — or the anti-anxiety drug alprazolam found in Box’s system when he died May 19 had been prescribed to him.

The death was ruled accidental, according to Box’s toxicology report released Tuesday.

The El Reno police are investigating how Box acquired the drugs without prescriptions.

The OU athletic department declined to comment.

Prior to the findings, Craig and Gail Box, Austin’s parents, told The Oklahoman they were not aware of their son having prescriptions for the pain-killers he was taking, likely to cope with pain from a back injury.

Box had a history of injuries while playing for OU. He suffered a knee injury in 2008 and missed most the 2010 season due to a back injury before returning for the last five games.

On Tuesday, OU athletic department spokesman Kenneth Mossman said when players like Box are injured and need to see a doctor, the department refers players to certain trusted physicians.

Players have the liberty to choose whether to go to the recommended physician.

Due to doctor-patient confidentiality, it is up to the student-athlete how much information about prescriptions or treatments to disclose to the athletic department, Mossman said.

» LINK: Read the toxicology report here.

EDITOR'S NOTE: This story will be updated throughout the day as more information is obtained.