ICAC officers had threatened to tell a police communications officer's wife about his extra-marital affair unless he co-operated with an investigation, the officer told a court yesterday. Tsang Ping-lam, 51, said the investigators had led him to believe he would receive immunity if he admitted leaking confidential information to a journalist. He told the District Court he initially agreed to act as a prosecution witness but changed his mind after he found out the Independent Commission Against Corruption would not keep its promise. Tsang has denied 12 charges of accepting an advantage. He is accused of giving confidential crime information to Apple Daily reporter Lau Kong-kwun in return for a $4,000 monthly payment. The prosecution alleges he received $116,000 from mid-1997 to November last year. Tsang asked the court to exclude as evidence his former admissions made to the ICAC, which he claimed were the result of threats and inducements. He said he was shocked when three ICAC officers approached him at his Fanling home on November 29 and said they knew everything about him. 'Mr Yang [Yan-tak, chief investigation officer] said they had monitored me for a while . . . they even knew I had an affair with Ms Fu [Tsang's colleague] and they said my wife would know about that if I stirred the matter up,' he said. Tsang said he agreed to 'co-operate' so that his family would not be harassed and because he believed he would not be charged. 'Mr Yang said Lau Kong-kwun had admitted paying me $4,000 each month for confidential police information,' he said. 'As I agreed to co-operate, I said the same when the interview was recorded.' But the ICAC still laid charges against him and avoided discussing the matter of making him a prosecution witness after the admissions were made, Tsang told the court. Another police communications officer, Yeung Kai-hing, 46, and Lau, 47, have pleaded guilty to corruption charges. They are scheduled to be sentenced next Tuesday. The case before Judge Richard Day continues today.