King died aged 89 on May 14 in Las Vegas, where he lived while he kept up a gruelling schedule of tours that ended only last year. King suffered from Type II diabetes for the last two decades of his life.
Two of his daughters — Karen Williams and Patty King — have alleged he was poisoned by his business manager Laverne Toney and his personal assistant, Eonline reported.
“I believe my father was poisoned and that he was administrated foreign substances to induce his premature death,” the daughters wrote in separate but identical affidavits, the entertainment site said.
“(I) request a formal investigation into this matter,” the court documents reportedly said.
Despite his legendary musical status, King’s final days were clouded by an apparent dispute between his family and manager over his care.
Toney, who is the executor of King’s estate, shrugged off the daughters’ charge.
“They’ve been making allegations all along. What’s new?” Toney said, according to Eonline.