Hayden Panettiere’s boyfriend Brian Hickerson administered Narcan to the “Heroes” actor on the day she died, according to his brother.

Zach Hickerson told TMZ that his brother Brian tried to revive the 36-year-old star with the nasal spray meant to counter opioid overdoses on Sunday afternoon. It was Zach who reportedly found Panettiere unresponsive in a chair when he arrived at the South Carolina Airbnb where the couple were staying. Brian was asleep in a bedroom.

Emergency service workers were called to the location, where they unsuccessfully performed resuscitation efforts on Panettiere before she was declared dead at 2:32 p.m.

Family, friends and colleagues expressed concerns that she and Brian had resumed their relationship, which included a history of domestic abuse. An attorney representing the actor’s boyfriend requested in a statement sent to the Daily News on Friday that the public allow investigators to do their jobs before jumping to any conclusions.

Hayden Panettiere boyfriend Brian Hickerson gave her Narcan day she died: brother

Raymond Hall/GC Images

Hayden Panettiere in Manhattan on May 19. (Raymond Hall/GC Images)

Zach similarly called for patience.

“There are a lot of assumptions, speculations and accusations currently swirling,” he told TMZ. “The truth will come out as the authorities complete and release additional details from the investigation. And that is important because the people who loved and adored Hayden deserve the truth.”

Neither Hickerson brother has been accused of wrongdoing. The Greenville Coroner’s Office said Monday that an autopsy revealed no indication of trauma that might have contributed to Panettiere’s death. A toxicology report is expected to help investigators determine a cause of death.

The actor wrote about battling substance abuse in her recently released memoir, “This is Me: A Reckoning,” but gave readers the impression that she was in recovery.

Friday would have been Panettiere’s 37th birthday.