The family of a Hunan businessman put to death in a "secret and hasty" execution vowed to keep fighting for justice yesterday as his cremated remains were returned home. The ashes of former property tycoon Zeng Chengjie were brought back to his home village of Yangshiao four days after he was executed by firing squad for illegally raising 3.4 billion yuan (HK$4.3 billion) and defrauding investors. The execution has ignited a public outcry because Zeng's relatives, who had been fighting to overturn his conviction, were not notified before the sentence was carried out on Friday. Zeng's family said they would continue to press for an explanation, while also seeking the release of Zeng's widow and elder daughter, who are both serving prison time for related crimes. "I can only sleep two hours a day at most, but I have a very strong spirit," said Zeng Xian, 25, the businessman's son. "I won't rest until I can get a reasonable response over the illegal procedures in my dad's case and his being executed without notifying us." I won't rest until I can get a reasonable response over the illegal procedures in my dad's case and his being executed without notifying us Zeng Xian The family does not accept the government's explanation that they did not have contact information for family members and that Zeng, 55, had not asked authorities to contact them. Yesterday the family performed ceremonies to mourn his passing and call his soul home. He is expected to be buried tomorrow after a memorial service. Zeng's younger daughter, Zeng Shan, 24, who went on a five-day hunger strike in Beijing to petition for her father's release, was stunned his death had come so suddenly. "I still had hopes of overturning this injustice," she said. "I can't believe it has happened. I somehow feel that he is still with me. I just wish I could have tried harder, knelt in front of courts and begged more reporters to expose the case." Although authorities have returned Zeng's remains, his children fear they may have withheld a final letter from him, as well as a will. "We were given a family letter written by him on June 1," Zeng Xian said. "It's just another family letter but my father did not know his life was soon coming to an end." Zeng Chengjie was convicted in May 2011 of illegally raising money to undertake three construction projects, in Jishou in western Hunan. His property was estimated to be worth 2.4 billion yuan but was sold cheaply to companies owned by the Hunan provincial government. Zeng Xian said he wanted people to know about his father's generosity. "I wish those who have been helped by my father will step forward and contact us, to show the public my father's real side," Zeng Xian said.