"Why the hell don't you just take the $300 million dollars mum has repeatedly offered you and walk away," Ginia Rinehart told her estranged sister Hope in a fiery email exchange.

The email, written two months after legal action was taken in 2011 by three of Gina Rinehart's four children to remove her as trustee of the multibillion dollar family trust, sheds light on the breakdown in the family relationship and suggests a secret deal had been offered to Hope to "walk away".

Threat to tell all: … Hope Rinehart. Photo: Jeff Atkinson

"You clearly do not want to be a part of our family, nor have you ever wanted to be part of the company, so take the money and walk away from everything! That way you can not have to deal with mum as trustee!," Ginia wrote to Hope on November 22, 2011.

In sharp contrast, Gina's son, John Hancock, had attempted to make his own secret deal with his mother - days before legal action was taken - in which he would receive a multimillion-dollar salary and a $15 million ''sorry payment'' for his mother's treatment of him over the years. Mrs Rinehart rejected his proposal.