The two eldest children of mining magnate Gina Rinehart have launched another blistering attack on their mother, launching a case which disputes the ownership of assets and shares within her multi-billion dollar empire.

The explosive new claim was served on lawyers for Mrs Rinehart, her flagship company Hancock Prospecting, and the two youngest Rinehart siblings Hope and Ginia at 7pm on Friday.

Facing new legal action: Mining magnate Gina Rinehart. Credit:Tony Ashby

By Monday morning, the iron ore baron, known for her litigious nature, had mobilised an army of legal representatives who had applied to have the case kept confidential and thrown out of court.