Three of Gina Rinehart's children want her removed as family trustee.
Australia's richest woman, Gina Rinehart, has lost her latest attempt to have a lawsuit brought against her by three of her children thrown out.
In the NSW Supreme Court today, Mrs Rinehart's application for summary dismissal was rejected by Justice Paul Brereton.
Three of her four children - John Hancock, Bianca Rinehart and Hope Rinehart Welker - were also granted leave to amend the case they bought against their mother in September last year.
The three plaintiffs want their mother removed as trustee of the family's multibillion-dollar trust, claiming she engaged in serious misconduct.
In July, they asked the court to consider new facts based on Mrs Rinehart's conduct since the case was first launched.
For the case to be summarily dismissed, Mrs Rinehart had to show the case is "hopeless", "without prospect of success" or "doomed to fail".
But Justice Brereton found it could be possible for the children to prove their mother is so unfit to be the trustee as to warrant removal.
"Of course, that is not to say that the plaintiffs will necessarily prove their allegations; nor that if proved the Court would necessarily be satisfied on the whole of the evidence that the first defendant was an unfit trustee; nor that the due administration of the trust warranted her removal. Those are issues that can be resolved only at a trial," Justice Brereton said.
The matter will return to court next week for directions and to consider costs.