THE sacking of Alex Tsui Ka-kit due to an undeclared association with a man under investigation by Mr Tsui's underlings raised internal questions about the ICAC's powers unprecedented in its 20-year history. The South China Morning Post understands Mr Tsui was sacked for not declaring an association with a man involved in an Independent Commission Against Corruption investigation. As deputy director of operations and the third most senior officer, the investigation files would have been crossing Mr Tsui's desk as part of daily reports of all ongoing operational matters. Mr Tsui met the man in Macau just hours after he was interviewed by Mr Tsui's underlings in June in relation to a shooting now before the courts. Both Mr Tsui, 46, and the man sit on the executive of the Hong Kong Boxing Association and had met in Macau on Thai boxing business. Neither has been charged with any offence and both still work voluntarily for the association. However, the link - uncovered after an internal investigation prompted by criminal intelligence related to the Thai kick-boxing fraternity - was found to be a clear breach of commission standing orders. ICAC Commissioner Bertrand de Speville felt he could no longer have any confidence in Mr Tsui and a summary dismissal was his only option, given the information Mr Tsui was privy to on a daily basis. The orders, strictly enforced by the commission at all levels, require an ICAC officer to make a report in writing to the commission as soon as possible after the officer discovers he has associated with a known criminal or someone under investigation. The internal investigation also checked if several ICAC investigations involving individuals, all believed to be members of the Sun Yee On triad group connected with the Thai kick-boxing scene, had been compromised. The individuals are all connected to the Hong Kong and Macau Muaythai Boxing Council, a splinter group from Mr Tsui's association, which has government and international recognition. Since his sacking, Mr Tsui has stood firmly behind the association, but distanced himself from the affairs of the council, which once staged a tournament at the Queen Elizabeth Stadium with the association in April 1992. Mr Tsui, who has repeatedly demanded that Mr de Speville make the reasons public, could not be contacted. The ICAC has officially refused to comment on the reasons for the Tsui sacking.