Billionaire Gina Rinehart's lawyers have rubbished two rival mining dynasties' multi-million dollar legal claims for iron ore riches from a project half-owned by Rio Tinto.
The complex court stoush that started in July pits Ms Rinehart's company Hancock Prospecting against the heirs of mining pioneer Peter Wright and engineer Don Rhodes over the massive Hope Downs mining complex.
Noel Hutley SC said there were multiple issues with DFD Rhodes and Wright Prospectings' cases as he began Hancock Prospecting's closing submissions in the WA Supreme Court on Tuesday.
He said most of those centred around their interpretation of legal agreements between Ms Rinehart's father Lang Hancock and his business partner Mr Wright and DFD Rhodes.
Mr Hutley also attacked the way Mr Wright and Mr Rhodes presented their cases, saying they had led with facts before attempting to address the agreements, which is "an approach at odds with the authorities".
"The closing submissions for the Rhodes parties address the construction of the 1969 agreement ... very few of those paragraphs referred to evidence of events, circumstances or things external to that agreement apart from two early agreements," Mr Hutley said.
He said Mr Wright's lawyers' closing submissions also addressed partnership agreements and "again, very few of those paragraphs refer to evidence surrounding circumstances apart from some documents using the term Hope Downs.
"Most of the factual controversies are presented as somehow relevant to alternative claims, especially claims for breach of fiduciary duty. But with respect neither (Mr Wright) nor the Rhodes parties have explained precisely how their alternative claims could succeed if the agreements are construed as we say they must be," he said.
"If (Wright Prospecting) or Rhodes party or both of them are not entitled to royalties, on the proper construction of the agreements or a particular royalty, which they claim, fiduciary relationship cannot be superimposed to confer any entitlement which the parties by apotheosis objectively never attended."
The Hope Downs mining complex near Newman is one of Australia's largest and most successful iron ore projects, comprising four open-pit mines.
Wright Prospecting has demanded a share of unmined and mined Hope Downs tenements and royalties, amid a claim that Hancock Prospecting breached 1980s partnership agreements.
DFD Rhodes is claiming a 1.25 per cent royalty share of Hope Downs' production, over an alleged deal with Mr Hancock and Mr Wright that saw it hand over tenements in the 1960s.
Ms Rinehart, Australia's richest person, is also battling her eldest children, who claim their grandfather left them a hefty share in the Pilbara mining resources he discovered in the 1950s.
Hancock Prospecting maintains it undertook all the work, bore the financial risk involved in the development at Hope Downs and is the legitimate owner of the assets.
About two dozen lawyers and company spin doctors have packed a Perth courtroom for the trial, which has also featured sensational claims against Ms Rinehart.
These include that the reclusive billionaire allegedly devised an unlawful scheme to defraud her children and threatened to have her father's former housekeeper Rose Porteous, who he later married, deported, and called her a "prostitute" and "oriental concubine".
The court has also been told Ms Rinehart lied about her father allegedly breaching his fiduciary duties to his company, and that Mr Hancock attempted to sever ties with his daughter in the years before he died in 1992.
Ms Rinehart inherited her father's iron ore discovery in WA's Pilbara region and forged a mining empire after he died.
She developed mines from the tenements at Hope Downs, signing a deal in 2005 with Rio Tinto, which has a 50 per cent stake in the project.
Her wealth is estimated to be about $36 billion and she is executive chair of Hancock Prospecting.
