The conviction rate in the city's bribery-related prosecutions fell 3 percentage points last year to 85 per cent, compared with 2006, the ICAC said yesterday.
The decrease came as the number of corruption reports, excluding election-related complaints, increased by 8 per cent to 3,600 last year.
According to the Independent Commission Against Corruption, 346 people were prosecuted and 296 convicted last year. In 2006, 341 people were prosecuted and 302 convicted. In his annual review of the commission's work, commissioner Timothy Tong Hin-ming said corruption remained well under control.
Although the number of reports concerning government departments fell by 9 per cent to 975, there were incidents of abuse of office, lack of diligence in supervision and undesirable association with contractors and suppliers.
Of the 975 cases, graft busters investigated 318 bribery reports against the police force, up from 298 in 2006. Although the number of reports concerning other government departments dropped by 15 per cent, there were 69 complaints against the Housing Department, an increase of 28 per cent compared with 54 in 2006.
Mr Tong said the ICAC would assign more resources to areas that were most vulnerable to corruption risks, especially those with a direct impact on people's livelihoods.
Meanwhile, the ICAC and the Guangdong Provincial People's Procuratorate have jointly conducted extensive research to produce a corruption prevention guide for small and medium-sized enterprises with cross-boundary operations.