AceShowbiz -

The official cause of Chris Kelly's death last May has been released. Per toxicology report, the former teen rap star had a fatal combination of drugs in his system when he passed away. The report supported his mother's statement to police after his death.

Investigators at the Fulton County Medical Examiner's Office didn't specify what kind of drugs he used, but his mother previously told police the Kriss Kross rapper had heroin and cocaine the night before he died. She also admitted her son had a long history of drug abuse.

Kelly a.k.a Mad Daddy was propelled to stardom with Chris Smith famously known as Daddy Mac under the moniker of Kriss Kross. They were best known for their hit single "Jump" from their 1992 debut album "Totally Krossed Out".

They once landed a spot on Michael Jackson's Dangerous world tour, and made a cameo appearance in his popular "Jam" music video.

Kelly was found unresponsive at his home in Atlanta on May 1 night. He was later pronounced dead at a nearby hospital. He was 34. Smith remembered his late best buddy as his brother. "Our friendship began as little boys in first grade," he said.

"We grew up together. It was a blessing to achieve the success, travel the world and entertain Kris Kross fans all around the world with my best friend. It is what we wanted to do and what brought us happiness. I will always cherish the memories of the C-Connection."