Evan Ellingson's death has been ruled an accident.
The 35-year-old actor was found dead in a bedroom at his residence in Fontana, California, earlier this month and after his autopsy took place in the days afterwards, a spokesperson for the San Bernardino County Sheriff's Department's coroner told People magazine he had passed away due to an accidental fentanyl overdose.
The 'Complete Savages' actor's father had previously told TMZ Evan - who hadn't been on screen for 10 years before his death - had struggled with addiction and died in a sober-living home.
Following Evan's death, his 'My Sister's Keeper' co-star Abigail Breslin paid tribute to him as a "a genuinely thoughtful person" who was the "life of the party" on set.
Abigail wrote on Instagram: "Evan Ellingson was a kind, funny and extremely talented human being. He played my big brother in a film I did called My Sisters Keeper. Evan was a genuinely thoughtful person who cared so much about turning in the best performance, which he accomplished. Some of his scenes in MSK still give me chills. He was also silly, funny, a prankster, a lover of Red Bull (I hated the smell of Red Bull [laughing emoji]) and he was energetic and the life of the party. I didn’t keep in touch a lot with him after the film, but he always stayed in my mind as a wonderful and sweet soul, one I am grateful to have crossed paths with. My prayers and condolences are with his family at this difficult time. (sic)"
Abigail also asked social media users to refrain from speculating about Evan's passing.
She added: "Evan, I know Heaven will welcome you with open arms. Your time on this earth may have been, devastatingly, short. Your humor, exuberance, kindness and bright light will linger forever. Sending you peace on your journey to the great beyond and who knows... maybe one day, I’ll meet you in Montana.
"Xx, abster
"Side note: the details of Evan’s passing have not yet been released. I ask you to kindly not speculate on the details out of respect for his family including his daughter. (sic)"