(CNN)Nick Gordon, the former boyfriend of Bobbi Kristina Brown, died from a heroin overdose, according to Florida's Districts 5 & 24 medical examiner's office.
The cause of his death was ruled as heroin toxicity, according to the autopsy report.
Gordon died in Seminole County on January 1 at the age of 30. The autopsy was performed the following day.
Caffeine, morphine and naloxone, a drug that reverses opioid overdoses, were among a series of substances found in Gordon's system, according to toxicology results.
He died three years after he was found liable in a civil case for Brown's death. He was was taken in by Whitney Houston when he was 12 years old and raised alongside the singer's daughter, Bobbi Kristina Brown.
Gordon and Brown became romantically involved after Houston's death in 2012, and tensions between the Gordon and Houston families over the relationship were part of the storyline on Lifetime's short-lived reality show "The Houstons: On Our Own."
Their relationship was thrust into the spotlight after it became public, followed by the death of Brown after she was found unresponsive in a bathtub in January 2015. She remained in a coma until her death six months later.
An autopsy declared that drug intoxication and immersion in water were the cause of the pneumonia and brain damage that ultimately led to Brown's death.
No criminal charges were filed against Gordon, but he was found legally responsible for Brown's death in a civil case and in 2016, was ordered to pay $36 million
to the estate of his late girlfriend. Gordon failed to appear for two hearings in the civil case in Brown's death, and her family won by default.
Randy Kessler, an Atlanta attorney who represented Gordon during his civil case, said his heart sank when he heard the news of his death.
"This is a tragic end to Nick's troubled life," he said.
Gordon's attorney, Joe Habachy, last month said despite Gordon's turbulent last few years, he was trying to stay away from drugs.
"He worked hard to hold his head up and stay sober and ... he genuinely wanted a happy healthy life with his family more than anything else," Habachy said. "My heart goes out to the family and friends Nick leaves behind and to any other families dealing with the losses and heartache caused by drugs."Read More