Gina Rinehart’s Hancock Prospecting has lost its bid to retain royalties from the mammoth Hope Downs iron ore project and will be forced to pay Wright Prospecting half of its royalties from the project, worth hundreds of millions of dollars.

In a landmark ruling in the Western Australian supreme court on Wednesday, justice Jennifer Smith said that Wright Prospecting had successfully made out its contractual claim to 50% of past and future royalties paid from the project.

But the court has dismissed Wright Prospecting’s claim to ownership in other mining assets held by Hancock Prospecting.

“It could be found that Wright Prospecting won half of its case and lost half of its case,” Smith said.

Sanjiv Manchanda and Garry Korte, senior Hancock Prospecting executives, were in the courtroom for the hearing.

A spokesperson for Wright Prospecting said it “welcomes the decision of Justice Smith delivered in the supreme court today”.

“Wright Prospecting commenced this action to recover our share of royalties from the Hope Downs 1-3 mines. That claim has been upheld. WPPL also sought either a proprietary interest or a royalty in the Hope Downs 4-6 mines and has been successful in its royalty claim.

“These proceedings were commenced in 2010 and, after many delays, we are pleased to finally receive a result in our favour. The decision is lengthy and complex. We will review it in detail before determining if any further steps need to be taken.”

The 1,656-page judgment was handed down more than two years after the complex legal case went to trial in Perth in mid-2023.

At the centre of the claim was rights to the 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 an $832m profit to Hancock Prospecting in 2025.

Wright Prospecting first launched legal action more than 15 years ago, arguing that the family business should share in the spoils arising from tenements that had been pegged out by Gina Rinehart’s father, Lang Hancock, and his prospecting partner, Peter Wright, in the 1950s.

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

The Wrights, and Rinehart’s children, John Hancock and Bianca Rinehart, each separately claimed ownership stakes in some of the mining plots where Hope Downs was developed.

Hancock Prospecting denied other parties owned the land or were entitled to royalties.

The company’s executive director, Jay Newby, declared victory after the judgment rejected those claims and found Hancock Prospecting and Rio Tinto were the project’s rightful owners.

“[Hancock] welcomes the ... decision which decisively confirms HPPL’s rightful ownership of these tenements firmly rejecting the baseless ownership claims of John, Bianca and Wright Prospecting Pty Ltd (WPPL) in their entirety,” Newby said.

“John, Bianca, WPPL and DFD Rhodes took no risk and made no meaningful contribution to developing the Hope Downs and East Angelas iron ore mines and infrastructure.”

John Hancock also claimed a partial victory in his long-running fight for a greater stake in Hancock Prospecting but said he wanted to put the feud in the past and reunite the family.

DFD Rhodes, the family business of Hancock’s and Wright’s business partner, Don Rhodes, won its claim to royalties on some of the disputed mining tenements.

Speaking outside the WA supreme court, Rhodes’ chief executive, Matt Keady, said that Hancock Prospecting and Gina Rinehart had been “formidable” opponents.

“We are very, very pleased that the judgment has recognised the contribution of Don Rhodes to the iron ore industry,” Keady said.

Hancock has estimated it would have to pay DFD Rhodes about $4m per annum and Wright Prospecting about $14m per annum, with Rio Tinto also set to pay some costs. Hope Downs mines have been producing iron ore since 2007.

The total quantity of payments was expected to be determined in a future hearing.

• This story was amended on 15 April 2026 to reflect that Hancock Prospecting must pay Wright Prospecting half of its royalties from the Hope Downs project, not half its earnings as a previous version stated.