BEIJING — Athletes competing at next year’s Olympic games in Beijing were told yesterday to avoid the city until the last moment because of its notorious smog, and once there to eat only in the Olympic village. The warning, from the head of Australia’s Olympic Committee, is an unwelcome shock to the organizers of the games.

John Coates, who is also a member of the International Olympic Committee, said Beijing’s pollution was a “prevailing worry.”

“We will be not recommending a long period in China before the Games,” he said. “That is only going to increase the possibility of respiratory or gastric illness, particularly if you are not living in the village.”

The new stadiums and transport infrastructure that Beijing has built for the 2008 games have received plaudits from around the world. But it is facing a wave of criticism on matters less directly related to sport, including human rights, Tibet, a series of scandals over food safety, from poisoned fish to contaminated bottled water, and air pollution.

Britain’s swimming team is to train in Osaka, Japan, until three days before their events in Beijing, instead of arriving 10 days in advance as usual. The Canadian team is said to be considering providing athletes with asthma inhalers, and Mr. Coates said Australian athletes would be arriving four or five days before their events.

He was meeting other IOC members including Jacques Rogge, its president, who will take part in a one-year countdown ceremony in Tiananmen Square tonight. They have been met by some of the worst smog for years, accompanied by unusually severe storms. The government has pledged to restrict the number of cars on the road during the games and to close down polluting factories.

Mr. Coates said food safety was less of a concern. But he added: “We will still be advising our athletes to eat in the village, not local food stores.” Precautions announced this week include satellite tracking of special lorries bringing food to the Olympic village.

At the press conference, the officials ducked questions about human rights. Yesterday, six overseas protesters abseiled down the Great Wall waving a banner saying “One World, One Dream, Free Tibet 2008” in English and Chinese. “One World, One Dream” is the games’ official motto.

Both Amnesty International and Human Rights Watch released critical reports marking the one-year countdown, while the press-freedom groups Reporters Without Borders and the Committee to Protect Journalists said moves to allow foreign correspondents to report more freely were “window dressing.”