The cause of death has been revealed for bodybuilding champion Hayley McNeff, who passed away unexpectedly at her home in Sudbury, Mass., on Aug. 8 at 37 years old.

The Massachusetts Executive Office of Public Safety and Security confirmed Monday that Hayley McNeff, a former fitness influencer and champion bodybuilder, died from “ acute intoxication ” due to a fatal mix of heroin, fentanyl, 4-ANPP, cocaine, and norbuprenorphine.

McNeff’s death was ruled an accident, according to the department’s Deputy Director of Communications, Brenna Galvin.

“Hayley was like a beam of light in this world. She had boundless energy and was very determined to achieve whatever she set out to do,” Hayley’s father, Dave, previously told PEOPLE in an exclusive statement.

“She set her sights on bodybuil

See Full Page