The anti-corruption body has lost two senior and experienced graft-fighters within three months - one headhunted to be general secretary of the police watchdog and the other leaving for personal reasons seven years before his retirement age. This departure of the two assistant directors has been followed by a reshuffle in the operations department of the Independent Commission Against Corruption (ICAC), which means the four assistant directors all have less than a year's experience at directorate level. The 800-strong operations department is the core unit of the anti-corruption body, where investigators are employed on contract terms that are renewed every 21/2 years until they reach the retirement age of 60. Ricky Chu Man-kin, 56, left in July for the Independent Police Complaints Council (IPCC), although he will not start his new job until January. Principal investigator Steven Lam Kin-ming was promoted to assistant director after Chu left. Jeremy Lo Kwok-chung, 53, will leave on Thursday. A well-known graft-buster, he worked for years in the operations department fighting police corruption before being transferred to the community relations department last year. Lo led the investigation team in the case of former police senior superintendent Sin Kam-wah, who was convicted of accepting free sexual services from prostitutes in 2003. The case triggered widespread public concern about the conduct of some senior police officers and led to a clash between police and the ICAC. Lo confirmed yesterday that he had decided to leave on the expiry of his current contract. 'Certainly I will miss the ICAC and my colleagues after working there for 30 years, six months and 19 days. This is the time for me to take a break,' he said, adding that he was leaving for 'personal reasons'. Having joined the ICAC in 1980, Lo said he had witnessed improving relations between police and the graft-buster in the past 30 years. One memorable experience was collaborating with the police in the 1990s in a vice-related corruption case in San Po Kong. 'We used the tactic of a Trojan horse with investigators hidden in a British Army truck near the vice establishment, so investigators could get in quickly,' he said. A dozen police officers were charged in connection with illegal gambling, conspiracy to rob, theft and indecent assault in this case. Rita Liaw will succeed Lo as assistant director for community relations. James To Kun-sun, deputy chairman of the Legislative Council's security panel, said Chu was suitable to be general secretary of the police watchdog. 'I don't have many worries about the succession in the operations department of the ICAC, as they still have capable investigators to deal with corruption cases,' To said. He said the current assistant directors of the department, while inexperienced at directorate level, had more than 10 years' experience of fighting corruption and could handle complicated cases including those involving digitalised methods.