Prince's Step-Sister Feared He'd Suffer A Heart Attack From 'Drug Use'

While Prince's shocking death is still under investigation, insiders are coming forward about what they are so far discovering and what secrets the 57-year-old may have been hiding from the public eye.

In a sneak peek of a new series by Reelz, renowned forensic pathologist Dr. Michael Hunter reveals that he's come across a transcript from Prince's step-sister Lorna Nelson, who allegedly claimed Prince was a heavy cocaine user.

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"Lorna, she was almost like a mother to Prince when he was growing up," said attorney Michael Padden. "She loved him very much. She was concerned about him as time went on and that's when she opened up to me about his drug use."

Padden went on, "Lorna felt that the drug use was so significant that he would die of a heart attack some day."

As previously reported, Prince's death from a drug overdose in April 2016 sent shockwaves across the world. His dark drug secret baffled fans who knew him as a fit, health-conscious star, who was vehemently anti-drugs.

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"She asked me that if something happened to Prince, that if he died under suspicious circumstances, she asked me to speak on her behalf about it," added Padden.

Autopsy: Prince airs Saturday, May 20 at 8 p.m. ET/PT on Reelz.