American Horror Story star Harry Haines' official cause of death has been revealed.

Less than two months after the 27-year-old Australian actor, musician and model's death, the Los Angeles County Medical Examiner-Coroner’s Office announced he died of an accidental fentanyl intoxication.

At the time, Hains' mother Jane Badler confirmed the devastating news in a heartfelt statement via Instagram, revealing her son "struggled with mental illness and addiction."

"He was 27 and had the world at his feet," the veteran actress wrote on January 9 just two days after his death. "A brilliant spark shone bright too short a time... I will miss you Harry every day of my life."'

A funeral service for Haines was held at the Hollywood Forever Cemetery on January 12.

Last month, Badler also shared another tribute, writing, "A lover of life ... a crazy, creative. Magical creature ... just on loan to spread magic .....#RIP Harrison George Hains. Heard you were flying around creating planets and new life forms."

Hains had appeared in television shows such as American Horror Story: Hotel, Netflix's The OA and Amazon Prime Video's Sneaky Pete, as well as performed music under the stage name Antiboy.

In March 2019 interview, he discussed his musical alter-ego, saying, "Antiboy is this character that I've created that is a gender-fluid robot from the future, stuck in a virtual reality world that has been malfunctioning.