ORGANISERS of Sydney's bid for the 2000 Olympics have expressed grave doubts about rival city Beijing's riot police and their ability to be ''non-lethal'' in the event of a Games riot. They have also warned about the quality of food, water and medical services available in Beijing, saying it is difficult to gauge the impact on foreign visitors of eating and drinking in the Chinese capital. The warnings come in an assessment of bids, prepared by the Sydney Olympics Bid 2000, a non-profit, government and business-funded company handling the Australian effort. Although more critical of its own effort than the International Olympic Committee (IOC) was in its recently released report, the Sydney assessment describes Beijing's bid as lacklustre and dull, and those of the other cities as open to doubt. The report, which compares the five major bidders - the others being Berlin, Istanbul and Manchester - according to 23 criteria, criticises Sydney's bid as having poorly explained economic statistics and projections for the year 2000. It also deems the Sydney bid to be lacking clarity in the section on Olympic village security, having a vague and unconvincing section on the Paralympics and an unappealing proposal for hosting the wrestling event. The analysis, based on a comparison of the five bid books, says Beijing lacks legislation requiring environmental impact studies before land is developed. It says the section on the Chinese Government is difficult to understand and the language - used to describe its enthusiasm for reform - is ''sometimes inappropriate and suggesting a police state - very authoritarian''. China's lack of experience in national and international television coverage is noted as a weakness, as is the Beijing bid's lack of an explicit provision for travel subsidies. Both Sydney and Beijing have promised free travel for athletes, but only the Australians have made a budget allocation to cover it. Even Beijing's motto - ''peace and progress for a better world'' - lands in the weakness column with criticisms including, ''no explanation of the formulation of motto and what it means''. But some aspects of Beijing's bid are complimented, including its strong cultural programme, its Olympic village bathroom facilities and strong local support. The report, which compares the bids under categories such as environment, security, transport, media, finance and sports experience, is critical of all the candidates. A spokesman for the Sydney organisers said the analysis was prepared in-house as a marketing tool.