The former child star died Nov. 5, with his body found in the bedroom of a residence in Fontana, Calif., per the San Bernardino coroner's office records obtained by E! News. He was 35.
One day after his passing, Ellingson's family spoke out on his longtime battle with addiction.
"Our family is heartbroken by the sudden passing of our beloved son, brother, uncle and friend, Evan," a Nov. 6 statement to NBC News read. "Evan was one of the most caring individuals who loved Jesus with all his heart. He had a sweet, child-like spirit with a smile that could light up a room. He was always thinking of others and wanted to use his own struggles with addiction to help people find hope."
His family shared that the actor had been three years sober but "recently relapsed" after being prescribed opioids following a dental procedure.
"He was passionate about pointing individuals to resources for help," they continued, noting Ellingson "often shared his journey of recovery" during speaking engagements.
"While in the end, he fell in his earthly battle with addiction, he was able to choose Jesus as his Lord and Savior and receive eternal life with Him," his family added. "We already miss Evan and cherish every moment of joy, laughter and love that he brought to us and so many others."
Ellingson—who played Jesse Fitzgerald in the 2009 movie My Sister's Keeper alongside Cameron Diaz and Abigail Breslin—told Access Hollywood at the premiere that it was an "awesome" experience for him.
"You can't really ask for a better cast. I haven't been in such a deep film so far in my whole life," he shared at the time. "I kind of feel like, this is just the beginning."
In addition to the role, Ellingson also appeared in the films Letters from Iwo Jima and Confession, as well as the TV shows 24 and Complete Savages. His final performance was playing Kyle Harmon in CSI: Miami from 2007 to 2010.
Authorities have not shared his cause of death. The manner of his death is listed in his records as pending.
According to his My Sister's Keeper costar Breslin, Ellingson is survived by a daughter.
"Evan Ellingson was a kind, funny and extremely talented human being," she wrote on Instagram Nov. 6. "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."
(E!, NBC News and Access Hollywood are all part of the NBCUniversal family.)
To see more of Ellingson's career over the years, keep reading...