The 30 year old was found dead at his Los Angeles home in February (15), and initial reports suggested he passed away from a suspected drug overdose.

Officials have since ruled he died from "acute heroin intoxication", according to the coroner's report obtained by E! News.

The documents also detail the state of Harris' home at the time of his death, as investigators noted "drug paraphernalia, including a spoon, syringe cap and remnants of latex balloons were recovered from the scene".

Wittels, who had previously battled drug addition and went to rehab twice, passed away just days before the Parks and Recreation series finale, which was dedicated to the producer and frequent guest star.

Following his death, tributes flooded in from friends and colleagues, including Parks and Recreation co-stars Amy Poehler, Rob Lowe and Aziz Ansari, and fellow comedians Seth Meyers, Ben Stiller and Sarah Silverman.