Los Angeles, Oct. 29 -- The death of Hollywood actor Hayden Panettiere has been ruled accidental, with police confirming that they have closed their investigation into the case.

Sgt. Diana Munoz of the Greenville Police Department confirmed the findings in a statement to PEOPLE, saying the decision was based on the medical examiner's "determination and the findings of the investigation."

Panettiere, known for her roles in 'Heroes' and 'Scream 6', was found unresponsive at an Airbnb in Greenville, South Carolina, on August 16, days before her 37th birthday.

The Greenville County Coroner's Office had earlier ruled her death an accident on September 22. The cause of death was determined to be the toxic effects of fentanyl, 4-ANPP, alprazo...