A Minnesota judge has dismissed claims from 29 would-be heirs to the estate of the late pop star Prince, strengthening the inheritance claims of the performer’s surviving siblings.

Carver County Judge Kevin Eide made the ruling on Thursday, adding that six people determined to be Prince’s siblings, half-siblings or other relatives would have to undergo genetic testing.

The denials of other would-be heirs came in response to a flood of individuals seeking a piece of the estate, estimated to be worth more than $US500 million ($A666.18 million), left by Prince when he died unexpectedly in April at the age of 57, apparently without a will.

There were accusations Prince had marriage records concealed by the CIA. Photo: Getty

Among the claims dismissed by Eide’s 19-page ruling was one by Georgia resident Claire Boyd, who said she had been married to Prince but that her marriage records were kept secret by the US Central Intelligence Agency.

Also denied were four people who claimed to be the singer’s children, as well as people claiming to be Prince’s father or other relatives.

The musician, born Prince Rogers Nelson, has long been identified in public records as the only son from Mattie Shaw’s marriage to John L Nelson, who also fathered Prince’s younger sister, Tyka Nelson.

Prince’s parents are both dead.

John Nelson, Norrine Nelson and Sharon Nelson are among five people who have been identified as surviving half-siblings of Prince.

Eide said there were no known disputes with their relationship to the singer but ordered the three and Tyka to undergo genetic testing.

The order did not address the remaining two half-siblings.

Eide ruled that two women who claim to be a niece and grand-niece of Prince made a strong enough case to being potential heirs that they would undergo genetic testing as well.