Prince’s estate advisors are in negotiations to license music from the artist's catalog and his much-vaunted archive of unreleased music for as much as $35 million, two sources close to the situation tell Billboard, although another source disputes that figure. All three major labels are in talks to license the music, the two sources said.

One source also said that a deluxe edition of Purple Rain -- which was announced as part of the artist’s 2014 deal with Warner Bros. but has not yet materialized -- will likely be released in the coming months, possibly as soon as early 2017. As Billboard previously reported, a new greatest-hits collection is expected to be released later this year.

The advisers -- estate advisers Charles Koppelman and L. Londell McMillan -- and reps for Prince's longtime label Warner Bros. declined comment or could not be reached for comment, although McMillan, who refuted this report on Twitter shortly after it was published, stressed to Billboard on Thursday (Oct. 20) that the proposals the advisers are considering are for licensing purposes only: The music is not for sale. He declined to comment beyond saying: "The vault is sacred ground: There is no sale. However, many do look forward to hearing the amazing music that Prince created in all of its forms.”

What exactly is in Prince's studio vault -- which contains thousands of hours of music recorded over four decades -- is unclear, as the estate is still sorting through the artist's assets and determining who will control the estate; sources say the estate has not yet begun cataloging the music in the vault. Ownership of certain unreleased material also remains unclear, as Prince was under contract to Warner Bros. from 1977 until the mid-1990s and subsequently cut one-off or short-term deals with every major label group (including Universal’s Republic, Sony’s Columbia, Epic and Arista, and EMI) and several indies as well as streaming services over the years.

When Prince’s 2014 deal with Warner Bros. was announced, the wording of the press release suggested that the artist at least verbally agreed to issue upgraded versions of his Warner Bros.-era albums and mine his vault for previously unreleased material, beginning with a Purple Rain deluxe edition. (Several contemporaneous tracks were released as B-sides and many more have appeared on bootlegs, and several full concerts from the Purple Rain era were professionally recorded, including a March 1985 show that was released on the now out-of-print home video Prince and the Revolution: Live.) But when asked about the status of the Purple Rain reissue shortly after Prince’s death, Warner Bros. chairman and CEO Cameron Strang told Billboard, "I definitely discussed it with Prince. At times he toyed with doing something with it and maybe worked on it, but he considered Purple Rain a masterpiece, and I think he liked it the way it was."

Prince apparently did not leave a will, which has made the management of the estate deeply complicated.

In June, Koppelman (who orchestrated Prince’s first post-Warner Bros. deal, with EMI) and attorney McMillan (who represented the artist several times over the years) were appointed musical advisers to Bremer Trust, the temporary administrator of the Prince estate. The announcement came just days after a Minnesota state judge granted Bremer limited authority to hire entertainment industry experts to help manage the music holdings. The two have been reviewing a large number of opportunities from major labels, major publishers and performance rights organizations, sources say.

Since his death on April 21, Prince has sold 1.95 million albums and 4.9 million song downloads in the U.S. through the week ending Oct. 6, according to Nielsen Music.

The case determining which of Prince’s family members will be officially declared heirs is ongoing. His sister Tyka and five half-siblings are likely to be declared the rightful heirs, but a judge is still deciding whether a purported niece and grand-niece and nephew should count as well.

The complexity around the estate reached another level last week when Prince’s Paisley Park studio complex in Chanhassen, Minn., opened to the public for just three days after a full opening had been announced. A wrench was thrown into the process just days before the opening when the city council voted against a rezoning request that would allow Prince’s estate to operate as a museum.

Updated at 10:45 a.m. ET on Oct. 21 to include L. Londell McMillan's comment and clarification that Prince’s assets are not for sale, but licensing proposals are being considered.