United Kingdom, Aug. 17 -- Audio of a 911 call suggests that Hayden Panettiere was found dead due to a suspected overdose.

The Heroes star died on Sunday (16.08.26) at the age of 36 after being found unresponsive by a friend at her apartment in South Carolina.

Now, TMZ has obtained dispatch audio of the call to emergency services, which appears to pick up officials discussing an "overdose".

The short recording includes one officer saying: "Responding. Overdose. CPR is in progress."

After receiving the emergency call, paramedics rushed to the apartment and tried to resuscitate Hayden using "advanced cardiac life support".

But after an hour, Nashville star Hayden was tragically pronounced dead at 2.32pm.

An official statement from the...