One migrant worker is dead and three are fighting for their lives after a suspected food poisoning case in southwest China's Yunnan Province, a local government official said on Friday.

Nine workers developed symptoms, including numbness of limbs, dizziness, fever, diarrhea and vomiting, Tuesday while working at a construction site near Biyuhe Village in Lanping County, the official with the county government said. They were taken to hospital immediately.

As of Friday noon, one had died, three had life-threatening conditions and the other five were under medical observation, the official said.

The official declined to reveal more details, including when the worker died and identities of the nine.

Local health authorities were investigating the cause of their illness, but had failed to draw a conclusion by Friday evening.

One of the experts who refused to be named said the workers could have been poisoned by food or water.

A resident in the Biyuhe Village, 4km from the construction site, said nobody in the village had shown similar symptoms.

(Xinhua News Agency February 28, 2009)