Hayden Panettiere's death: The DEA is assisting in the investigation, while the autopsy finds no signs of trauma

The Drug Enforcement Administration (DEA) has joined the investigation into the death of actress Hayden Panettiere, as reported by TMZ on Wednesday. The outlet indicated that agents from the federal agency are assisting with the parallel investigations that were already underway following the actress' death.

Panettiere died Sunday at age 36. She was found unconscious and in cardiac arrest in an apartment in Greenville, South Carolina. Resuscitation efforts were unsuccessful, and the actress from "Nashville" and "Remember the Titans" was pronounced dead at the scene.

Fox News Digital confirmed that preliminary autopsy results showed no signs of trauma that contributed to her death.

According to a police report obtained by the outlet, the on-and-off partner of Panettiere, Brian Hickerson, and his brother Zach called 911 after finding her unconscious. Hickerson later handed over to authorities a bag of medications that, he said, the actress had been taking. Authorities executed a search warrant at the home and, on Wednesday, conducted a follow-up visit to a residence in South Carolina linked to the Hickerson brothers, though no one answered the door.

Panettiere's death came just weeks after the actress spoke openly about her history of addiction and the decisions she made while seeking help. The New Yorker began acting as a child, appearing in the soap opera "One Life to Live" at age 4, and later shared the screen with Denzel Washington in "Remember the Titans" before playing Claire Bennet in "Heroes." She later played singer Juliette Barnes in "Nashville," a role that earned her two Golden Globe nominations. 

In an interview with People in 2022, Panettiere recounted that she began taking "happy pills" at age 15 before her interviews, and that over time she began drinking and using opioids as her career took off. She also addressed part of that period in her memoir, "This Is Me: A Reckoning," and last month she spoke with Fox News Digital about her decision to let her daughter, Kaya, live in Europe with her father, former boxing champion Wladimir Klitschko, after concluding that a custody battle would ultimately harm the child.

Weeks before her death, Panettiere recorded one of her last public appearances alongside PETA, an organization with which she collaborated to call for an end to the captivity of dolphins in marine parks. The organization released the video as a tribute following her death.

Panettiere is survived by her daughter, Kaya.