The letter from law firm Corrs Chambers Westgarth, referenced in an interlocutory judgment by the court last month, claims Bianca leaked confidential company documents to her brother John Hancock while she was a director of her mother’s flagship mining company, Hancock Prospecting (HPPL). Mr Hancock was not an officer of the company or employed by it at the time.
It claimed she breached the Corporations Act and three confidentiality agreements with the company.
“This unlawful and dishonest conduct was effected, in part, by Bianca Rinehart sending herself confidential HPPL information from her HPPL email address,’’ the letter, written in March, said.
Bianca’s lawyers declined to comment last night.
Mr Hancock and Bianca, the two eldest Rinehart children, have been fighting to gain control of the family’s Hope Margaret Hancock Trust, which holds a 23.4 per cent stake in HPPL.
This unlawful and dishonest conduct was effected, in part, by Bianca Rinehart sending herself confidential HPPL information from her HPPL email address
Corrs Chambers Westgarth, Gina Rinehart's lawyers
Gina Rinehart, Australia’s richest person, resigned as trustee last year, while denying claims by the pair that she acted with “gross dishonesty” in her trust dealings.
Bianca, who was once considered a successor to the family business and once worked for Rio Tinto, is being put forward by Mr Hancock as his preferred trustee.
Ms Rinehart’s youngest daughter, Ginia Rinehart, is backing her mother’s push for an independent trustee to be appointed.
Ms Rinehart’s other child, Hope Welker, is now taking a “neutral” position.
Bianca will be among the first witnesses to give evidence in the hearing, which has been set down for two weeks.
Although she grew up in a mansion, was taught to fly a helicopter and attended the famous US school Phillips Academy, where former US presidents George Bush Sr and Jr were educated, Bianca has described herself as being “this poor little Australian lost soul” as a child.
She told Vogue magazine in 2012 that she slept with “a hammer under my mattress” as a child when public interest in the family intensified after her grandfather Lang Hancock married his maid Rose Porteous.