Police in Las Vegas have launched a homicide investigation into the death of BB King after the blues guitar legend’s daughters accused his aides of poisoning him.

King died at age 89 on May 14 in Las Vegas, where he lived while he kept up a gruelling schedule of tours that ended only last year.

Two of King’s daughters – Karen Williams and Patty King – allege he was poisoned by his business manager Laverne Toney and his personal assistant.

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“I believe my father was poisoned and that he was administered foreign substances,” Patty King and Williams say in affidavits provided to The Associated Press by their lawyer, Larissa Drohobyczer.

“I believe my father was murdered,” they say.

“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.

Drohobyczer said she represents Williams, Patty King and most of King’s nine other adult children and heirs.

“The family is sticking together … to oust Ms Toney based on her illegal conduct, conflicts of interest and self-dealing,” she said.

She alleged that Toney hastened King’s death by “misconduct, or by failing to properly attend to his medical needs”.

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.

A lawyer for King’s estate also dismissed the daughters’ accusations as “ridiculous”.

“I hope they have a factual basis that they can demonstrate for their defamatory and libellous allegations,” Brent Bryson said in a statement.

Earlier the local coroner confirmed the homicide investigation and said that King’s remains would undergo an autopsy.

Given the timeframe for the autopsy, King’s funeral in his beloved Memphis has been postponed, local media reported.

Riley B King was born in poverty and grew up working in cotton fields, but went on to master the guitar and entered the music business after travelling to Memphis and working for radio stations.

He became known as the Beale Street Blues Boy, which eventually earned him the moniker BB King.