Lawmakers last night vowed to plug loopholes in the civil service system to prevent 'collusion between officials and businesses', when they authorised a select committee to probe the Leung Chin-man affair. The 12-member investigation panel, which will be given statutory powers to demand papers and witnesses, will look into the approval process for retired senior officials working for businesses and investigate whether Mr Leung, the former housing director, was involved in any conflict of interest. Mr Leung was cleared last year by the government to work for property developer New World Development, one year after his retirement. But during Mr Leung's time as director of building, director of housing and permanent secretary for housing, planning and lands, he had approved several controversial projects - including one to sell a public housing estate in Hung Hom to New World. The incident sparked a public outcry. 'The Leung Chin-man affair made the public realise top officials can still ... make big money after retirement,' Democratic legislator Cheung Man-kwong said during the debate. 'We will plug loopholes to prevent collusion between officials and businesses.' Mr Leung has since resigned from the post. A government review panel on the post-retirement employment process was quickly set up, but it failed to pacify outraged Hongkongers, nor prevent a subsequent plunge in Chief Executive Donald Tsang Yam-kuen's popularity. In yesterday's debate to formalise the creation of the select committee, which was supported by both government allies and pan-democrats, lawmakers were united in saying the integrity of the civil service must be maintained. Lee Cheuk-yan of the Confederation of Trade Unions said the committee should probe whether it was a common practice for officials to provide benefits to businesses and be rewarded by them with positions or other benefits after retirement. 'We cannot allow these new forms of corruption to happen,' Mr Lee said. Liberal Party chairwoman Miriam Lau Kin-yee said loopholes in civil service rules should be addressed, while independent Cyd Ho Sau-lan said top officials should be banned from joining private businesses after retirement. But Lau Kong-wah, of the Democratic Alliance for the Betterment and Progress of Hong Kong, said: 'We should not begin the investigation with a verdict already in mind.' Secretary for the Civil Service Denise Yue Chung-yee, who had been criticised for her lack of political sensitivity in approving Mr Leung's post-retirement appointment, said the government would respect the decision to set up the investigation. She said that in light of public concerns, the government's review panel would seek public views soon and submit a report by June.