Angus Cloud died of acute intoxication following an accidental overdose.
The actor - who was best known for playing Fezco in the HBO drama series 'Euphoria' - passed away on July 31, aged 25, and his cause of death has now been confirmed by the Alameda County Coroner.
The coroner has revealed to PEOPLE that the actor had cocaine, methamphetamine, fentanyl, and benzodiazepines in his system at the time of his death.
Benzodiazepines are depressant drugs that can be used to treat a variety of conditions, such as anxiety disorders and insomnia.
Angus' death was announced by his family back in July.
In a statement given to CNN, his family said at the time: "It is with the heaviest heart that we had to say goodbye to an incredible human today.
"As an artist, a friend, a brother and a son, Angus was special to all of us in so many ways.
"Last week he buried his father and intensely struggled with this loss. The only comfort we have is knowing Angus is now reunited with his dad, who was his best friend.
"Angus was open about his battle with mental health and we hope that his passing can be a reminder to others that they are not alone and should not fight this on their own in silence."
Angus' family also described his death as a "devastating loss".
They added: "We hope the world remembers him for his humour, laughter and love for everyone.
"We ask for privacy at this time as we are still processing this devastating loss."
Meanwhile, an HBO spokesperson paid a glowing tribute to the actor.
The spokesperson told CNN: "We are incredibly saddened to learn of the passing of Angus Cloud. He was immensely talented and a beloved part of the HBO and 'Euphoria' family.
"We extend our deepest condolences to his friends and family during this difficult time."
