Attorney Benjamin Cassiday III has died, ending his multi-million-dollar court claims that his father and uncle misused assets of a family trust fund for their personal benefit.

Michael Rudy, attorney for Cassiday, confirmed that Cassiday, 57, died last week at The Queen's Medical Center. He had been suffering from cancer.

Cassiday attended only the first few days of a Circuit Court trial concerning his legal claims against the trustees of the Charlotte Harriet Lucas Cassiday trust.

Rudy said the case will continue, however, because the interests of minor beneficiaries and even unborn beneficiaries of the trust would be affected if Cassiday's claims are found to have merit.

"It's really a very rare and unusual set of circumstances," Rudy said. "There are beneficiaries who have not yet been born whose interests will be affected by the outcome of this case."

Douglas Smith, the court-appointed attorney acting as a guardian of those beneficiaries' interests, declined comment yesterday.

Proceedings in the case have been on hold since last week, pending a decision from Circuit Judge Bert Ayabe on whether the trustees of the trust breached their fiduciary duties and are liable for financial damages.

At a status conference with attorney involved in the case yesterday afternoon, Ayabe asked for additional legal arguments to be submitted to him by next week, said Margery Bronster, attorney for one of the trustees, Benjamin Cassiday Jr.

Cassiday Jr. and his brother Paul Cassiday, the other trustee, have denied any wrongdoing.

Much of the case centers on a commercial real estate venture in San Diego in the 1980s that was financed in part with funds from the trust. In addition to acting as trustees of family funds, Ben Cassiday Jr. and Paul Cassiday also had personal stakes in the real estate venture.

Both men said they fully disclosed details of the venture to their mother and that she approved the deal before she died in the early 1980s.

The trust received all moneys owed to it as a result of the investment, the Cassiday brothers said.

Ben Cassiday Jr., 85, is a retired U.S. Air Force brigadier general. Paul Cassiday, 79, served as a trustee for the massive James Campbell estate for 20 years before retirement.

If Ayabe rules that the trustees are liable for financial damages, a second phase of the trial would then be held to determine the amount owed, Rudy said.

"We calculate that damages could range as high as $15 to $20 million," Rudy said.

There could be additional litigation against attorneys or law firms that provided legal advice to the trust, he said.

Similar malpractice claims originally brought by Ben Cassiday III against another, related family trust resulted in a $4.15 million jury verdict against that trust's law firm in 2006, according to court records.

The trust later negotiated a reduced settlement figure, which is confidential, according to court files.

The Cassiday family traces its roots in Hawai'i to the arrival here in 1811 of British sea captain Alexander Adams. Adams served in the Navy of King Kamehameha I and later received title to properties including Niu Valley and Hawai'i Loa Ridge on O'ahu.

Other descendants of Adams include auto dealer and developer James Pflueger as well as Bishop Estate trustee and Polynesian navigator Nainoa Thompson.

Information about funeral services for Cassiday was not available yesterday.