The family-run Chinachem Charitable Foundation has filed a High Court writ demanding PricewaterhouseCoopers replace accountants Deloitte Touche Tohmatsu as administrator of the estate of the late Nina Wang Kung Yu-sum. The trust, controlled by Wang's siblings, has asked the court to appoint Rainier Lam, Victor Jong and Peter Yu of PricewaterhouseCoopers as the joint administrators. The Court of First Instance will hear the case on November 21. Deloitte was appointed by the court in 2007 to oversee the fortune - estimated at between HK$50 billion and HK$100 billion - of the woman who was Asia's wealthiest. The trust, headed by Wang's brother, Kung Yan-sum, believes Deloitte's charges are too high. Kung was also not happy with the firm interfering with the operation of the trust and of the Chinachem Group. He claims that on several occasions Deloitte refused to allow the trust to make donations. The latest court battle comes two weeks after the conclusion of a long-running fight over Wang's estate between Tony Chan Chun-Chuen - who claimed he and Wang were lovers - and the trust. The Court of Final Appeal dismissed the self-styled fung shui master's claim to any of Wang's fortune. Deloitte said the firm was appointed by the court in 2007 to preserve Wang's estate and that its duty was to carry out the court's orders independently. 'Inevitably our role as impartial guardians of the estate has not always been palatable to some of the parties affected,' a statement said.