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Blues legend BB King died of natural causes primarily stemming from Alzheimer's disease, the Las Vegas coroner's office has confirmed.

King's death was also attributed to coronary artery disease, diabetes, heart failure, high blood pressure and brain damage from low blood flow.

Two of his daughters had alleged King was poisoned by long-time associates.

"We can say with confidence that Mr King died of natural causes," said Clark County coroner, John Fudenberg.

King died on 14 May at the age of 89.

Coroners said they determined King's cause of death after conducting an autopsy, toxicology tests and consulting a neuropathologist.

They also found that, while King had suffered strokes, they did not kill him.

'Measure of closure'

The star's daughters, Karen Williams and Patty King, alleged in May that he had been given "foreign substances to induce his premature death" by his business manager Laverne Toney and his personal assistant, Myron Johnson.

The women added that "King was sequestered from all family members" in the week before his death, and that Toney and Johnson were the only people with him.

But the coroner found no evidence to prove the allegation of poisoning.

"Ms Toney and Mr Johnson are very happy that these false and fictional allegations that were made against them by certain of Mr King's children have been dispelled," said Brent Bryson, a lawyer for King's estate.

"Hopefully we can now focus on the body of musical work that BB King left the world, and he can finally rest in peace."

The coroner added: "Our condolences go out to the family and many friends of Mr King, and we hope this determination brings them some measure of closure."

King was born on 16 September 1925 to sharecroppers and worked in the cotton fields as a child before picking up the guitar.

Considered one of the world's greatest players, he was known for his sharp single notes and vibrato on the electric guitar he christened Lucille.

With hit songs such as The Thrill Is Gone, Three O'Clock Blues and Darlin' You Know I Love You, he influenced generations of guitar players. The musician was later inducted to both the Blues Foundation Hall of Fame and the Rock and Roll Hall of Fame.

He was married twice and had 15 natural and adopted children, 11 of whom are still alive.