(Reuters) - Music superstar Prince left no known will when he died last week, his sister said in court documents on Tuesday listing his six siblings or half-siblings as heirs to a legacy estimated at hundreds of millions of dollars.

The sister, Tyka Nelson, asked that a special administrator be appointed to handle Prince’s affairs and that she be appointed to probate his estate.

In documents filed in a state court in Carver County, Minnesota, Nelson listed herself and five other siblings or half-siblings as Prince’s heirs but gave no value of his assets or debts.

Prince, born Prince Rogers Nelson, was married and divorced twice. Under Minnesota law, Prince’s assets are likely to be split evenly between the siblings, according to attorney Stephen Hopkins.

The value of his music catalog alone has been estimated at over $500 million, according to Prince’s first manager, Owen Husney. That included potential licensing rights for film, TV, commercials and videogames that Prince rarely exploited, Husney said last week.

The influential singer, musician and songwriter behind hits like “Purple Rain” was found dead at age 57 on Thursday in an elevator at his Paisley Park Studios compound in a Minneapolis suburb. The cause of death was not yet known.

Michael Kosnitzky, a New York- and Miami-based attorney who advises the extremely wealthy, said he was surprised Prince had died without a will, given the artist’s tendency to control his image, likeness, name and recordings.

“... That he would put himself in a position that he would lose control of those things at death I found very surprising,” Kosnitzky said.

“What is to stop someone who controls his estate from saying that they’re going to promote purple Skittles?” he said, referring to Prince’s signature color and the popular candy, adding that he did not think Prince would approve.

In her court filings, Nelson said she did not know of the existence of a will and had “no reason to believe that the Decedent executed testamentary documents in any form.”

She proposed the Bremer Bank in Minnesota as special administrator, saying it had done business for years with Prince.

Since his death, sales of his albums have soared; more than 2.3 million songs and some 580,000 albums have sold since Thursday, according to Nielsen Music. [nL2N17S1QA}

Aside from royalties from his more than 30 albums, Prince regained ownership of his master recordings after a dispute with his Warner Bros. TWX.N music label.

He was also said to have a cache of unheard recordings, including an album cut with late jazz trumpet great Miles Davis.

Hopkins, the Minnesota attorney, predicted a long, drawn-out case over Prince’s assets, probably lasting years.