The number of corruption complaints against the construction industry has dropped - the first fall in the sector since the uncovering of a series of piling scandals over the past three years. The Independent Commission Against Corruption received 137 complaints against the construction industry in the first seven months this year, 15 per cent down from the 162 cases in the same period last year. The anti-corruption watchdog released the figures after the conclusion last week of two of the highest-profile cases involving short-piling work on Home Ownership Scheme buildings. The fall reversed the rising trend over the past three years. In 1999 there were 183 complaints, 261 in 2000, and 296 last year. The cases uncovered include the short-piling scandals at two HOS blocks - Yuen Chau Kok in Sha Tin and a residential project above Tung Chung MTR Station. In the Yuen Chau Kok case, three people from a subcontractor company were jailed for up to 12 years last Tuesday after being found guilty of conspiracy to defraud the Housing Authority in 1998. Twenty-one of the 36 piles in two of the blocks concerned were found to have been shortened by two to 15 metres, while 11 rested on soft mud instead of bedrock. Only four were the length specified in the contract. The two blocks were demolished in 2000 at a cost of $542 million. In the Tung Chung case, an engineer responsible for supervising the foundations for the site in 1997 was jailed last Friday for three years and nine months for covering up a defective pile site after receiving free trips and entertainment from subcontractors. Three former staff from the main contractor were jailed in 2000 for between two and five years. Investigators later found 72 of the 76 piles at the site to be defective. ICAC senior investigator Arthur Leung Kai-wing said cover-ups used in short-piling scandals included shortening tape measures, using false concrete dockets and submitting false construction records. Acting group head of the ICAC's Corruption Prevention Department, Mok Wah-hoi, said lax supervision and inappropriate contact between construction site supervisors and contractors were among the common corruption problems in the industry. But the ICAC's programme co-ordinator, Helen Lee Ching Po-han, said it had noticed a gradual improvement in the industry after educational talks had been stepped up at construction sites over the past two years.