One of the world's richest women has lost control of her family's multi-billion Australian dollar fortune after a bitter court dispute within her family, it was reported on Thursday.

The New South Wales (NSW) Supreme Court determined Gina Rinehart's eldest daughter Bianca was best suited to control the family trust.

Gina Rinehart is the daughter of Lang Hangcock who established Australia's iron ore industry after discovering vast reserves in Western Australia's Pilbara region.

The court said it was clear Rinehart had "gone to extraordinary lengths" and used "enormous pressure and great influence" to control the trust throughout the proceedings.

The court said Rinehart was likely to influence any trustee who tried to move against her interests.

The claim was launched in September 2011 and alleged Rinehart acted "deceitfully" and with "gross dishonesty" in her dealings with the trust.

Rinehart changed the end-date of the trust to 2068, after contacting her children in early September 2011, days before when it was originally due to expire.

One daughter, Hope Welker, left the action in March 2013 after settling for 45 million Australian dollars (34.7 million U.S. dollars) claiming she was suffering a "high degree of stress."

In October 2013, Rinehart stepped down from her role as trustee to end the legal battle, however the issue of who would be the fortune's trustee remained.

Rinehart's wealth is currently estimated at 12.2 billion U.S. dollars and is preparing to begin production on her 10 billion Australian dollar (7.7 billion U.S. dollar) Roy Hill iron ore project in Western Australia's Pilbara region.

In October 2014, Bianca Rinehart and Rinehart's son John Hancock launched an action in the Federal Court claiming their mother defrauded them of billions of dollars in profits from the Roy Hill, Hope Downs and Mulga Downs iron ore projects.

Development for the new iron ore mine on the family's cattle ranch at Mulga Downs has shut down from the ongoing legal issues.