An arts foundation housed in a $100 million Santa Barbara oceanfront mansion, stipulated in a contested will of copper heiress Huguette Clark, may not become a reality.

Negotiations are underway between an army of lawyers, the New York attorney general and 19 of Clark's distant relatives. The distribution of Clark's $307 million estate is under contention with the relatives (the majority of whom never met Clark) want her property to be sold.

Whether Clark's will is upheld or thrown out will be decided in a jury trial scheduled for September 17 in Surrogate’s Court in Manhattan.

The Santa Barbara estate, Bellosguardo, would house an art collection worth millions, according to reports by NBCNews.com investigative reporter Bill Dedman whose book on the saga, Empty Mansions, written with Paul Clark Newell Jr., will be published by Ballantine Books next month.

Clark, who died at age 104 in 2011, left nothing to her relatives, the descendants of her father’s first marriage, in her second will. The relatives maintain that she was mentally ill and incompetent, and the victim of fraud by her nurse, attorney, and accountant.