The mystery continues about just who entered the winning $1.09 billion bid for a piece of Hunghom real estate on Monday, further proof that the Government should examine and revise its land auction rules. This need is compounded by the perception that Cheung Kong (Holdings), which dropped out of the bidding early while acting in its own name, may be the secretive winner. There's nothing wrong with any property company making more than one effort to acquire an attractive tract. It might, for example, bid both on its own and in partnership - ready to carry the full cost up to a certain point but willing only to share expenses if the bids go higher. But these auctions are of public assets sold to raise revenue to meet public needs; they are not selling art objects to adorn private rooms. This creates a legitimate civic interest in ensuring that sales are conducted with a maximum of transparency and a minimum of concealment. The public needs to know that sales are above board, without even a hint of collusion to hold down prices in an unethical manner. The sale in question appears to have been conducted entirely within the existing rules; no one suggests anything illegal has occurred. The winning bidder, the otherwise unidentified Sino China Enterprises which appears to be legally lodged in an empty office, has posted the required $50 million deposit and doesn't have to pay the full price for nearly four weeks. Cheung Kong so far declines to explain its possible role in all this. For the record, it says 'we cannot deny that we have no involvement' but calls it 'quite a complicated matter'. Because of its other holdings in Hunghom, Cheung Kong had been expected to dominate the auction. However, Deputy Chairman Victor Li Tzar-kuoi proffered only one low bid, followed by a conspicuous exit. With the biggest player gone, Sino China Enterprises eventually won for a price much below market expectations. There have been many calls for complete revision of government land policy, on the grounds the existing system keeps prices too high and makes Hong Kong uncompetitive in the world at large. Short of that, however, the rules could be amended to require that agreed minimum prices be made public, so all bidders would know where the real contest begins. And they could insist that all bidders be identified, giving the public full confidence that the contests are real.