A toxicology screening revealed that Kelly, 34, had a mixture of drugs in his system when he was pronounced dead on May 1, said Betty Honey of the County Medical Examiner's office in Atlanta yesterday.
Paramedics found Kelly unresponsive on a living room couch at his Atlanta home and tried to resuscitate him. Kelly, known as "Mac Daddy," was later pronounced dead at a local hospital.
Honey said she did not know which specific drugs Kelly had used before his death. However, a police report from the night of Kelly's death said his mother told investigators her son used cocaine and heroin the night before he died and had a history of drug abuse.
Their first and most successful song was the 1992 hit "Jump," which became a chart-topper in the United States and around the world. The two were never able to match the tremendous success of their first song, though they had other hits like "Warm It Up," and "Tonite's tha Night."
Earlier this year, Kris Kross performed in Atlanta to celebrate the anniversary of Dupri's record label So So Def and Williams said Kelly was planning to make a comeback.