ICAC investigation tactics were challenged in the District Court yesterday for the second time in two months when a stay of prosecution was sought in a corruption trial. The anti-graft body allegedly covertly taped a suspect's conversation with his lawyers, breaching the Basic Law. Lawyers for senior executives Shum Chiu, Wong Hung-ki, Yu Chi-wai and Wong Tin-sum, who all face corruption and false accounting charges, argued that the Independent Commission Against Corruption breached the common law and the constitutional right to confidential communication with a lawyer. The four allegedly bribed government engineer Chan Kau-tai, the father of Canto-pop singer Eason Chan Yick-shun. Chan was jailed for seven years in January. 'The ICAC engaged in conduct which was such a breach of the fundamental rights of the accused as to strike at the very heart of the integrity of our system of administration of justice,' Peter Duncan SC, for Yu and Wong, told Deputy District Court Judge Julia Livesey. Mr Duncan said the ICAC breached two articles of the Basic Law. Article 35 recognises that communications between lawyers and their clients are confidential and privileged. Article 30 states that law-enforcement agencies may only use bugging devices in accordance with legal procedures, but since there are no laws in Hong Kong governing the use of hidden cameras and microphones, this was not allowed, Mr Duncan said. He cited a ruling by District Court Judge Fergal Sweeney in April that because of this legislative gap, the ICAC could not introduce evidence obtained by such covert means in court. It is alleged that the defendants - two directors, a president and a financial controller from four Housing Authority suppliers - conspired to offer advantage to Housing Authority officers to get on an approved list of suppliers used by the department. Bribes are alleged to have totalled $1.9 million and the defendants are also accused of forging 16 purchase orders worth more than $3.2 million. The ICAC arrested a man named Tang Hop-sing in May 2002 for conspiring with the four to offer advantages to a Housing Authority officer. Tang told investigators he would fully co-operate if the ICAC did not charge him. The ICAC then recruited him as an 'undercover agent', to continue working at ABB (Hong Kong), where Yu and Wong were president and financial controller respectively. In November that year, the ICAC raided ABB and arrested Wong. Yu was out of town at the time and met a lawyer about the case when he returned. Unaware that Tang was working with the ICAC, he asked Tang to join the meeting with the lawyer. The ICAC arranged to audio-tape the meeting covertly. Mr Duncan called on the court to conduct a balancing exercise between the constitutional rights and public protection from crime. No pleas were taken and the hearing on the permanent stay on prosecution continues today.