Attorneys for BB King’s estate have ridiculed claims by two of the blues musician’s heirs that he was poisoned and police have said there is no active homicide investigation.

Three doctors determined that King was appropriately cared for in his final days and received 24-hour care and monitoring by medical professionals “up until the time that he peacefully passed away in his sleep”, attorney Brent Bryson said on Monday.

Daughters Karen Williams and Patty King have alleged family members were prevented from visiting while King’s business manager, LaVerne Toney, and his personal assistant, Myron Johnson, hastened their father’s death.

Toney is named in King’s will as executor of an estate that, according to court documents filed by lawyers for some of King’s heirs, could total tens of millions of dollars.

Johnson was at BB King’s bedside when he died on 14 May in hospice care at home in Las Vegas, aged 89. No family members were present.

“I believe my father was poisoned and that he was administered foreign substances,” Patty King and Williams say in identically worded sections of affidavits provided by their lawyer, Larissa Drohobyczer. “I believe my father was murdered,” they say.

An autopsy was performed on Sunday. Test results would take up to eight weeks to obtain and should not be affected by the fact that King’s body had been embalmed, said Clark County coroner John Fudenberg.

Fudenberg issued a statement on Monday saying there was no immediate evidence supporting the murder allegations, and Las Vegas police lieutenant Ray Steiber told the Associated Press there was no active homicide investigation.

Toney and Johnson each declined to comment on the accusations, though Toney said: “They’ve been making allegations all along. What’s new?” Toney worked for King for 39 years and had power of attorney over his affairs.

A week before King’s death, a judge in Las Vegas dismissed a request from Williams to take over as guardian. A 29 April petition alleged Toney had blocked King’s friends from visiting him and had put her family members on King’s payroll. It also alleged that large sums of money had disappeared from King’s bank accounts.

But Clark county family court hearing master Jon Norheim said on 7 May that police and social services investigations in October and April uncovered no reason to take power of attorney from Toney.

The allegations come days after a public viewing in Las Vegas drew more than 1,000 fans and mourners, while 350 people attended a weekend memorial for family and friends. A Beale Street procession and memorial are scheduled on Wednesday in Memphis, Tennessee, followed by a Friday viewing and Saturday burial in King’s hometown of Indianola, Mississippi.