In emails urging his sister Bianca Rinehart to join him in legal action against their mother Gina Rinehart over their trust fund, John Hancock repeatedly called her 'the fat' and 'fatty'. The emails were tendered as the daughter of mining magnate Gina Rinehart was reduced to tears after being forced to sign a deed against her interests, the Federal Court in Sydney heard. Bianca Rinehart, along with her brother John Hancock, lodged a Federal Court to increase their stake in the family company, Hancock Prospecting, according to the ABC. Scroll down for video . Happier times: John Hancock (left) and his mother Gina Rinehart meet the press together in 2002 . Bianca Rinehart appeared in a Sydney court to give evidence in an ugly legal battle over the family's finances . However, emails between 2004 and 2006 were tendered showing Mr Hancock told his sister 'Fat would have quickly grown tired of supporting your shopping and leisure activities' and 'hopefully you will have another man to take care of you', in the aftermath of her break up with swimmer Grant Hackett, The Daily Telegraph reports. 'You can send my correspondence and your reply to fatty (in hoping she will pay for your Mandarin education), but at the end of the day you will still come off second best,' Mr Hancock wrote in May 2004. Nearly a decade later, the siblings are united in a bitter trust dispute against their mother, the richest person in Australia. Ms Rinehart's lawyer, Christopher Withers, said his client had been effectively bullied into signing an agreement regarding her grandfather's second wife Rose Porteous. 'Your honour will see from Bianca Rinehart's evidence that she felt threatened and isolated,' Mr Withers said. 'She was distressed and crying in Hancock Prospecting's offices. We say that the inequality of bargaining power was palpable.' 'This is a young woman who was compelled by her mother and Hancock Prospecting to sign a deed against her will.' Ms Rinehart also told the Federal Court she became aware her personal email account had been hacked, and said 'all of my emails have been deleted, which I didn't do', according to Fairfax Media. The Rinehart children currently control 23 per cent of the company, while Gina Rinehart has a stake of more than 76 per cent. The siblings want to access to records of mining profits, and accused their mother of defrauding them of billions of dollars. Ms Rinehart, along with her brother John Hancock, lodged a Federal Court to increase their stake in the family company, Hancock Prospecting . However, Counsel for Gina Rinehart countered the claims of Ms Rinehart by asserting she was dishonest in her sworn affidavit in regards to what she  was told about the family's mining interests. Ms Rinehart was also asked if she printed confidential emails and stored them in her office when she was a director of Hancock Prospecting, while under cross-examination from her mother's lawyers. Ms Rinehart said she printed important emails needed to be kept, but she denied storing them in the office. 'That would be quite stupid of me to do,' she said. The Rinehart siblings have accused their mother of defrauding them of billions of dollars, and are disputing ownership of assets and shares the family's mining companies . She said she kept the emails at home and that, at one point, her work emails had been 'compromised'. She also denied the emails related to company information she had previously accused her mother of willfully hiding from her. Ms Rinehart leaves the Federal Court in Sydney after giving evidence on Monday afternoon . Mining magnate Gina Rinehart, pictured with her father, Lang Hancock (left) is the Asia-Pacific's richest woman . Rinehart was asked if she printed confidential emails and stored them in her office when she was a director of Hancock Prospecting, while under cross-examination from her mother's lawyers . Gina Rinehart's lawyers have previously argued the case should be handled in private due to potential commercial impact to projects, such as the multi-billion-dollar Roy Hill mining project in Western Australia. The current case is not connected to the lengthy battle for control of the Hope Margaret Hancock Trust set up by Rinehart's father, Lang Hancock.
Gina Rinehart called 'the fat' and 'fatty' by son John Hancock in emails .
'Fat would have quickly grown tired of supporting your shopping,' he said .
Nearly a decade later, the siblings are united in a bitter trust dispute .
Bianca Rinehart gave evidence in the dispute into the family's finances .
Ms Rinehart was forced to sign contracts, and left 'distressed and crying'
Children of Gina Rinehart lodged case to increase stake in family company .
Siblings currently control just 23 per cent of family's Hancock Prospecting .
Gina Rinehart has a stake of more than 76 per cent in the company .