Manny Pacquiao knocked out Britain's Ricky Hatton last weekend
Health officials in the Philippines have asked the country's star boxer to delay his return from the US as a precaution against swine flu.
Manny Pacquiao was scheduled to return home on Friday, after his knockout victory against Britain's Ricky Hatton in Las Vegas at the weekend.
But Philippine Health Secretary Francisco Duque urged the champion to postpone his flight.
There is no suggestion that the boxer actually has swine flu.
But his fight last weekend was in Las Vegas, where confirmed cases of the H1N1 virus have been reported.
The health secretary told reporters he wanted Mr Pacquiao to delay his triumphal return to the Philippines until at least next Tuesday.
Mr Duque explained that it takes about five days for swine flu symptoms to appear, and he was hoping Mr Pacquiao and his entourage would impose "self-quarantine" until then, to be absolutely sure they had not contracted the virus.
The Philippines was due to hold a "national day of celebration" for Mr Pacquiao this Friday, in honour of his win.
But Mr Duque said there were concerns that the motorcade, which was due to drive through Manila in celebration, could pose a risk of spreading the virus.
There are no confirmed swine flu cases in the Philippines, although some patients are under observation.
According to the latest figures from the World Health Organization, nearly 1,500 people around the globe have been infected with swine flu, most of them in Mexico.
Two fatalities have been reported in the United States.