Hayden Panettiere's Family Notified That Her Remains Are Ready For Release, Official Says

Hayden Panettiere's family has been notified by a South Carolina coroner's office that her remains are ready for release -- after the actress died of a possible drug overdose, TMZ has learned.

A rep for the Greenville County Coroner's Office tells TMZ ... they have advised Hayden's parents that her body is ready to be turned over to them.

But the rep says the family has yet to choose a funeral home ... so, for now, Hayden will stay with the coroner's office.

Once the family picks a funeral home, then Hayden's remains will be officially turned over to them, according to the rep.

Meanwhile, the coroner is conducting toxicology tests after Hayden's autopsy was completed Monday, with her cause and manner of death still pending.

The coroner's rep says tox tests usually take 8 to 12 weeks ... they will be testing for alcohol, medications and illicit and non-illicit drugs.

As we reported ... Hayden was found dead Sunday inside a Greenville apartment by a friend who called 911 to report an "unresponsive female" in "cardiac arrest," police said.

It's unclear if the friend who discovered Hayden is on-again, off-again boyfriend Brian Hickerson, with whom she's had a rocky relationship over the years.

Dispatch audio, obtained by TMZ, revealed that first responders performed CPR on Hayden ... and we confirmed Narcan was found in the apartment.