Hayden Panettiere's death ruled accidental by South Carolina police

The death of Hayden Panettiere has been ruled accidental, South Caroline police announced Wednesday.

Greenville Police Department said the investigation into Panettiere's death has been concluded "based on the Medical Examiner's determination and the findings of the investigation," and the actor's death was officially ruled accidental.

Last month, a South Carolina coroner confirmed Panettiere died from an accidental drug overdose that included fentanyl. There were no signs of trauma, the coroner's office said.

Emergency responders were called to a residence where Panettiere, 36, had been staying in Greenville, South Carolina, on the afternoon of Aug. 16. Despite "advanced cardiac life support measures," she was pronounced dead there, the Greenville County Coroner's Office said.'

Panettiere's on-again, off-again boyfriend Brian Hickerson and his brother Zach were at the scene of her death, according to a police report obtained by CBS News . The Hickersons made the 911 call that brought first responders to the apartment.

Authorities, including the Drug Enforcement Administration, were investigating the circumstances of Panettiere's death. Police previously said that a preliminary investigation "has not indicated any signs of foul play or suspicious circumstances."