More police promotion boards will be set up to minimise the chances of corruption under a new system to go on trial from next week. The change is the result of a review after a bribery scam involving the promotion of constables to sergeants was exposed in November. Management briefed the four officers' associations on the new system, which will have a year-long trial from Tuesday, when 9,000 constables can apply for 250 sergeants' posts. Police chiefs considered recommendations from the Independent Commission Against Corruption's graft prevention unit before finalising the new mechanism. A major change is to increase the number of assessment boards from four to 15 to lessen the chance of candidates being interviewed by their immediate seniors. Candidates will be told which board to attend only a week before the interviews scheduled, to start in September, compared with one month's notice before. Short-listed constables will need to sit for one interview instead of two. But a board of review comprising a senior superintendent and two superintendents will scrutinise the interview results of the 15 boards. The Local Inspectors' Association said the new arrangement was better because the old system sometimes produced contradictory comments on a candidate from his two interview boards. Association chairman Tony Liu Kit-ming suggested non-police be included on the assessment boards to better prevent corruption. Chairman of the Junior Police Officers' Association Lau Kam-wah said: 'The increase in the number of boards and shorter notification period can help minimise chances of corruption.'