Sports authorities in Shanghai have recommended the suspension of all sporting events in the city as a result of the coronavirus outbreak.
The move casts further doubt on the Chinese Grand Prix, scheduled to be held in Shanghai on 19 April.
Its viability will be discussed by Formula 1 bosses on Wednesday.
The Shanghai Sports General Association instructed sports bodies to suspend events until the threat from the virus is over.
They were told to “formulate a plan for epidemic prevention to avoid internal infections” and to “implement a daily hygiene management system and strengthen health education to urge employees to protect themselves”.
F1 was not immediately available for comment but, within the sport, there is a growing belief that the Chinese Grand Prix will have to be at least postponed from its scheduled date.
And with a record 22-race programme this season, finding a new date for it in an already crowded calendar would not be easy.
At an F1 event on Tuesday evening, unveiling the second series of the sport’s collaboration with Netflix, some senior team insiders were even questioning whether the inaugural Vietnamese Grand Prix could be at risk.
That race is scheduled to be held on 5 April in the Vietnamese capital Hanoi, about 100 miles from the Chinese border.
However, there have been only 10 cases of the virus in Vietnam – two fewer than Australia and Germany – so the risk appears remote for now.
Chinese health authorities are stepping up efforts to control the spread of the virus, with approximately 18 million people in the east of the country now required to stay at home.
In Wuhan, the epicentre of the virus, 11 large public venues including sports arenas are being turned into makeshift hospitals to provide an additional 10,000 beds for the sick. Two new hospitals have been built there since the outbreak started.
The World Health Organisation has declared a global health emergency over the outbreak but said it did not yet constitute a “pandemic”, or the worldwide spread of a new disease.
The virus outbreak has led to the cancellation of a number of sporting events in China, including the World Athletics Indoor Championships in Nanjing, scheduled for 13-15 March, and a race of the all-electric Formula E series in Sanya the following weekend.
Olympic organisers also say they are “seriously concerned” about the spread of the coronavirus and the impact it could have on the Tokyo Games in Japan this July and August.