Australia’s richest person, Gina Rinehart, could be forced to share some of her iron ore riches with two rival mining dynasties after losing parts of a bitter legal stoush.

The battle pitted Mrs Rinehart’s company, Hancock Prospecting, against the heirs of mining pioneer Peter Wright and engineer Don Rhodes amid allegations of decades-old contract breaches.

Justice Jennifer Smith handed down her more than 1600-page judgment in the West Australian Supreme Court in Perth on Wednesday.

Wright Prospecting and DFD Rhodes won some of their claims for royalties from the massive Rio Tinto-operated Hope Downs mining complex in Western Australia, she said.

“Wright Prospecting won half of its case, lost half of its case, and Hancock Prospecting and its subsidiary Hope Downs has won and lost half of its case,” Justice Smith said as she discussed costs with the parties.

Wright Prospecting had demanded a share of unmined and mined Hope Downs tenements and royalties amid a claim Hancock Prospecting breached a 1980s partnership agreement.

DFD Rhodes also claimed a royalty share of Hope Downs’ production over an alleged deal with Mrs Rinehart’s father Lang Hancock and Mr Wright that handed over tenements in the 1960s.

The bruising encounter also drew in Mrs Rinehart’s reclusive children, over a previous claim by the eldest, John Hancock and Bianca Rinehart, stating their grandfather left them a hefty share in the Pilbara mining resources he discovered in the 1950s.

Mining giant Rio Tinto was also a party in the Supreme Court battle as the joint venture partner in Hope Downs and could be on the hook for part of the settlement.