Penniless Jewish refugee David Hamilton later became a millionaire businessman – and set aside a nest egg to protect against a repeat of the Holocaust in case fascism returned.
He wanted to provide for his children from a tax haven fund if their assets were ever under threat.
But the High Court heard Germanborn Mr Hamilton’s plan split his children, 69-year-old accountant Alan and barrister Carolyn, 64.
Alan says he was deprived of his fair share of the £3.2million fund when his father died nine years ago aged 84.
Carolyn says she was given £2.2million, while Alan got £1million, because she was a “good daughter” to the fashion and property tycoon.
She said of her New York-based brother: “He’s behaved very poorly, in a spiteful, mean and nasty way”.
She said his case amounted to calling their father a fraud who moved his money overseas to avoid paying tax.
She added: “My father lost his family, his home, his country and his community. He lost everything. He was always concerned that it would happen again; he would say that you’re never ever safe.”
Mr Hamilton fled Hitler in 1938 on one of the last evacuee ships to leave Nazi Germany.
He died leaving an estate valued at about £4.5million, out of which he gave £500,000 to his widow Laura, and the remainder, divided equally, to the children.
He also left them the Liechtensteinbased Rainbow Foundation containing the disputed £3.2million.
His son says it forms part of his father’s UK estate and should be split equally.
The case continues.