A building site agent due for release from prison last month after serving six months for a piling scam will have to serve another four years. The Court of Appeal ruled yesterday that the original sentence handed down on Ko Chi-kwong, 43, for conspiracy to defraud was inadequate. He had been due for release on September 28. One of Ko's accomplices, project manager Li Che-hing, 51, saw his jail term increase from one year and nine months to five years. Another, site engineer Yu Chun-man, 29, had his term increased to two years from one year and nine months. Mr Justice Simon Mayo, Mr Justice Arthur Leong Shiu-chung and Mr Justice Frank Stock heard the Government's application to review the sentences on September 19. In a written judgment handed down yesterday, they said the sentences were 'manifestly inadequate' and 'wrong in principle' for such serious offences. 'It has to be said immediately that this was a very serious offence which carries a maximum of 14 years' imprisonment,' Mr Justice Mayo said. 'What is involved is a major public safety issue. The failure to comply with the necessary requirements almost inevitably will subject any buildings erected on the site to the grave hazard that they might collapse and thus cause loss of life and severe injuries to the occupants of the building.' The appeal judges said a starting point of 10 years' jail 'would be in no way excessive' for anyone instigating a short-piling scheme. The initial trial judge, District Court judge Richard Davies, was criticised for having put 'far too much weight' on the defendants' personal circumstances and the submissions that 'they had only acted in the way they had to avoid being dismissed'. Yu had pleaded guilty to conspiracy to defraud the Buildings Department and the developer of the Tung Chung Station project on March 22. The other two were found guilty of the same charge on June 2. The court heard that senior management of their employer, I-P Foundations, had instructed staff to make the piles shorter to meet the tight schedule and avoid being penalised for delays. No charges have been laid against the management.