A legal challenge led by a prominent New York art collector against Sotheby’s over the scheduled auctioning off of Jean-Michel Basquiat’s “Flesh and Spirit” has been denied by the state supreme court. This curious legal contretemps involves Hubert Neumann, the revered contemporary art collector and disinherited husband of Dolores Ormandy Neumann, champion of downtown New York graffiti artists, and their daughter Belinda, who is leading the effort to sell the mythic Basquiat. In the suit against Sotheby’s, and by proxy his own daughter, the elder Neumann claimed that if the courts don’t step in to block the sale, the Basquiat piece would be “lost to the people who love it, and New York forever”—despite the fact that it’s been hidden in the family’s collection, unseen, for nearly 35 years.

The 12-foot-by-12-foot painting was purchased by Mrs. Neumann for $15,000, after seeing at a 1983 group show at Tony Shafrazi Gallery. It was one of the opening salvos in Basquiat’s ferocious and incandescent art career, a towering assemblage of multiple canvases, overlaid with howling snippets of text in oil pen, interspersed with bits of human physiology. It’s estimated to go for upwards of $30 million at the auction, which is still scheduled for May 16.

The Basquiat’s turn as a star witness in the Neumann estate feud started after the September 2016 death of Mrs. Neumann. The lawsuit claimed that daughter Belinda coerced her mother to modify her will while in a heavily medicated state of mind. The alteration led to Mr. Neumann’s removal from the estate. The suit also claimed that Sotheby’s “botched” the marketing of the Basquiat painting and was “shamelessly willing to capitalize on a difficult family situation”

For his part, Mr. Neumann has long been considered an eccentric crank, disinclined to institutionalize his own massive art collection, which includes works by Picasso, Miro, Matisse, Jeff Koons, yet paranoid that one day it would be preyed upon by collectors like vultures in the sky. As a New York Times profile from 1997 would seem to reveal, his crankiness was more a deep-seated disgust for capitalistic hunger of contemporary collectors. “Museums are no longer about art,” he said in the piece, “They’re about maintaining a life style.”

In a statement to The Art Newspaper, Mr. Neumann said: “Flesh and Spirit is an American treasure…I will happily sacrifice my entire economic interest in the painting to ensure that it becomes available for study and public exhibition. Sotheby’s broke its word to Hubert Neumann and prioritized short-term profit and prestige over its contractual obligations and doing the right thing.”

The paper has also confirmed that Mr. Neumann will challenge the ruling.