Gina Rinehart faces the possibility of losing billions of dollars in riches from her Pilbara iron ore empire and her mantle as Australia’s wealthiest person when a long-awaited court verdict is delivered in Perth on Wednesday.

The Western Australian supreme court judgment will rule on whether Rinehart must share the spoils of some of Hancock Prospecting’s most lucrative iron ore projects with the family of her late father’s business partner.

At stake is billions of dollars in royalties and assets arising from the tenements pegged out by her father, mining pioneer Lang Hancock, and his business partner Peter Wright, through the Hanwright partnership in the 1950s and 1960s.

At the centre of the claim is the lucrative Hope Downs mining complex near Newman in north-west Western Australia which is a joint venture between Hancock Prospecting and Rio Tinto, and which delivered $832m profit to Hancock Prospecting in 2025.

The Wright family heirs, including billionaire Angela Bennett and her nieces Leonie Baldock and Alexandra Burt, claim they are entitled to an equal share of the 2.5% royalties coming from Hope Downs to Hancock Prospecting, saying Wright Prospecting never relinquished the assets held by Hanwright.

Hancock Prospecting rejects the claim for both past and future royalties, arguing it undertook all the work, bore the financial risk of development and is the legitimate owner of the Hope Downs assets.

In another claim that forms part of the leviathan case, the family business of late prospector Don Rhodes says it is entitled to a 1.25% share of the contested royalty stream.

The judgment, which comes more than two years after the complex legal case went to trial, is expected to be appealed regardless of the outcome, further prolonging the bitter stoush that has been running for close to two decades.

Justice Jennifer Smith will also rule on a claim brought against Rinehart’s company by two of her own children, John Hancock and Bianca Rinehart, who have accused their mother in proceedings of an “egregious fraud” against them.

The children claim that their mother was responsible for transferring assets out of a trust following Lang Hancock’s death in 1992, stripping them of valuable tenements that they argue they should have had the right to develop.

The trust comprised part of an alleged 49% shareholding of Hancock Prospecting held by the children that is also in dispute.

After being enjoined to the case by the Wright family in 2016, the children are hoping the judgment will rule that they are entitled to royalties and profits from a swag of projects developed by Rinehart following Hancock’s death, including the linchpin of Rinehart’s empire, the Roy Hill mega mine.

Rinehart and Hancock Prospecting have rejected all claims, with Rinehart’s lawyers saying her actions in moving mining assets back to her company were done to right an historic wrong by her father.

They allege Hancock shuffled company assets as he sought to maintain the “lavish” lifestyle of Rinehart’s nemesis stepmother, Rose Porteous.

Wednesday’s supreme court ruling will also inform a separate federal arbitration process being led by former WA chief justice Wayne Martin that will decide how Hancock Prospecting’s shares are divided between the family.

While John and Bianca launched the claim for their alleged entitlement, all four of Rinehart’s children stand to benefit if the court rules in their favour.

Hancock Prospecting has rejected the claim, however its latest annual report shows that more than $6.4bn in dividends have been placed in reserve pending the outcome of arbitration.