Credit: Instagram @arianagrande

Back in September, rapper and former boyfriend to Ariana Grande, Mac Miller, was found in his San Fernando home, pronounced dead of a supposed overdose. Following a tribute concert held for the artist earlier last week, reports have surfaced, confirming his cause of death.

According to TMZ, Miller was found in the praying position by his assistant before the authorities were called. Unable to revive him, he was pronounced at the scene. The L.A. County Coroner’s Office has just released the toxicology report, finding that the overdose was caused by a “mixed drug toxicity” – involving fentanyl, cocaine and alcohol.

It is said that the amount of each drug found in his system was not a lethal dosage, but its the combination that ultimately killed him.

Miller has struggled with substance abuse for years, and in May of this year he was arrested for a DUI and hit-and-run.

Shortly after his death, Ariana Grande took to Instagram, expressing sympathy for his passing. “i adored you from the day i met you when i was nineteen and i always will. i can’t believe you aren’t here anymore. i really can’t wrap my head around it. we talked about this. so many times. i’m so mad, i’m so sad i don’t know what to do. you were my dearest friend. for so long. above anything else. i’m so sorry i couldn’t fix or take your pain away. i really wanted to. the kindest, sweetest soul with demons he never deserved. i hope you’re okay now. rest.”