'Big Spender' Cheung Tze-keung held out against mainland interrogators for months after his arrest until he learned his alleged accomplices had been caught, it emerged yesterday. Evidence from a 'grass' eventually turned the cat-and-mouse investigation in the police's favour, a Guangdong Public Security Bureau report said. Cheung is being detained with 17 other Hong Kong men and 14 mainlanders in Guangzhou for a chain of crimes, including the kidnapping of two tycoons whose families paid more than $1.6 billion in ransom. The report said Cheung's arrest thwarted his audacious plans to bomb Stanley prison, free gangster Yip Kai-foon and kidnap a third tycoon to repay his massive gambling debts of $300 million. Cheung, 44, was said to appear arrogant when first questioned at the heavily guarded rural Guangdong detention centre on January 26. Sources said Cheung gradually dropped his defence months later when he learned key accomplices, whom he had demanded to contact, had also been arrested. A bureau report said two top officers were appointed to lead the questioning of Cheung, but the confirmation of his identity alone had taken hours to complete. When Cheung was asked his name, he replied: 'My name is Chan Hing-wai.' Asked about the name of his wife, he replied: 'I don't have any wife. I don't have any family members. I'm alone.' The report said Cheung admitted his identity only when the officers read out the names of his family members. After checking the interrogation notes, Cheung signed the last page and drew more than 70 lines on the empty space to make sure nothing could be added. 'I can only say, I lose tonight,' Cheung then told the officers. Another Hong Kong suspect, Wu Chai-shu, claimed he was Thai businessman 'Chan Shu-kwong' and had no family members. Wu had suspected the officers were SAR police: 'If you are Hong Kong police, I'll not say a word.' The breakthrough came in April when five interrogators won the co-operation of another Hong Kong suspect, Cheung Chi-fung, who is hoping to get a lighter sentence by co-operating. Cheung Chi-fung revealed the name of another alleged gangster, Cheung Chi-ho, and the murder of Choi Chi-hung by convicted gunman Yip Kai-foon. The grass, who married when he was 50 and has a baby son, said he remembered how Wu went to Guangzhou to plan for an abduction last August 25 because it was the day before he had a banquet to celebrate the birth of his son.