Hayden Panettiere died after taking fatal black-market pill

 Hayden Panettiere reportedly died hours after taking a fatal black-market pill.

The Heroes and Nashville star allegedly took an oxycodone pill that was laced with fentanyl on the morning of her death aged 36 last month.

Fentanyl is a man-made drug that is up to 50 times stronger than morphine.

Panettiere bought several black-market prescription drugs from her “long-time drug dealer” in Los Angeles the day before she flew to south Carolina with boyfriend Brian Hickerson, law enforcement sources told TMZ.

The Drug Enforcement Administration (DEA) in Los Angeles is reportedly trying to trace the pill back to her alleged dealer.

The exact cause of Panettiere’s death will be confirmed when the toxicology results come in, which could take up to 12 weeks.

Panettiere’s long-term boyfriend Hickerson is believed to have administered Narcan, a medication used to treat drug overdoses, to the unresponsive actor before paramedics arrived.

The DEA in south Carolina and LA are leading the investigation alongside south Carolina police, according to TMZ.

Hickerson is thought to have spoken with DEA officials but it is not known what he revealed to them. He previously told police that Panettiere had a “bag of medication” with her.

The drugs Panettiere was reportedly taking were redacted by police, although there were nine different types.

She was found unresponsive and in cardiac arrest on August 16, with a post-mortem examination finding there were “no signs of foul play or suspicious circumstances”.

Her family said she will be remembered as an “incredible light” who brought “immeasurable love and joy to all who knew her”.

Panettiere’s ex-partner, former boxer Wladimir Klitschko, said his family is “going through a time of profound shock and grief”. The couple dated from 2009 to 2018. Their daughter was born in 2014.

In 2018, Panettiere gave Klitschko full custody of their daughter Kaya, now 11, as she struggled with alcohol addiction, opioid use and post-partum depression.

She found fame playing cheerleader Claire Bennet in the superhero drama Heroes before going on to star as up-and-coming country singer Juliette Barnes for six seasons on the hit TV series Nashville.

Her performances in Nashville earned her two Golden Globe nominations for best supporting actress while her singing on the show produced 11 entries on the US Billboard Hot Country Songs charts.

Panettiere’s film credits include 2006’s Bring It On: All Or Nothing, comedy-drama film Raising Helen, and appearances in Scream 4 and Scream VI as Kirby Reed.

Following her rapid rise to fame, the pressure of the industry began to weigh on Panettiere – with the actress previously revealing that she had struggled with addiction throughout her 20s.

Her father Skip described her as “an incredible light and a force of nature who brought immeasurable love and joy to all who knew her – and to the millions who watched her onscreen”.

He asked that her family be given privacy as they “take time to process this unimaginable loss”.