The FBI is investigating the death of former Indianapolis Colts owner Jim Irsay, according to a report.

The bureau is also investigating the recovery doctor who provided Irsay with prescription pain pills and ketamine in the last months of his life, according to documents reviewed by The Washington Post and two sources.

Irsay died in May while vacationing at the Beverly Hills Hotel in California. He was 65.

The Post reviewed a federal grand jury subpoena that showed the FBI is seeking records and information relating to Irsay’s death, his “substance (illegal and prescription) use,” and his “relationship with Dr. Harry Haroutunian,” a prominent addiction specialist based in California.

The U.S. District Court for the Central District of California in Los Angeles issued the subpoena earlier this month. Federal agents visited Indianapolis for several days over the past few weeks, according to two anonymous sources, and interviewed multiple people who were close to Irsay over the final years of his life.

A spokeswoman for the FBI’s Los Angeles field office did not immediately reply to the Post's request for comment Thursday. The Beverly Hills Police Department, which initially investigated Irsay’s death, has not been contacted by the FBI, according to a department spokesman.

Colts Chief Legal Officer Dan Emerson told the Post on Thursday that the team is aware of the investigation but has not been served with a subpoena or contacted by the FBI.

“I do understand that there have been some subpoenas provided, but not to me, the Colts or any of our current employees,” Emerson said, declining to comment further.

Haroutunian did not respond to the Post's requests for comment.

The recovery doctor was staying at the Beverly Hills Hotel and overseeing the treatment of the former National Football League coach. He signed Irsay’s death certificate, which stated that the cause was cardiac arrest caused by pneumonia and heart issues. There was no autopsy, and Beverly Hills police closed their investigation into the death days later.

The Post reported in August that Irsay, who had publicly claimed to have kicked his addiction to pain pills, had secretly relapsed and was receiving opioid pills and ketamine injections in the final months of his life from Haroutunian in amounts that alarmed several people close to him.