The head of China's quality watchdog has resigned amid a growing scandal over melamine-contaminated milk.
The official Xinhua news agency reports Li Changjiang stepped down "with the approval of the State Council", China's cabinet.
Earlier, Prime Minister Wen Jiabao apologised for the contamination, which has made nearly 53,000 children ill.
Four children have died and about 13,000 remain in hospital, 104 of them reportedly in a serious condition.
The problem was first revealed two weeks ago, when milk powder from the Sanlu Group was found to contain melamine, an industrial chemical.
At least 22 other companies have since become involved in the scandal.
Milk products made by the Yili, Mengniu and other groups have been recalled from supermarket shelves in China and many other countries.
The Sanlu Group is 43% owned by Fonterra, New Zealand.
Estimates of the number of people affected have jumped in recent days, probably as the result of checks by health officials, who looked at hospital records from May this year to trace the origins of the contamination.
Xinhua said Mr Li, whose agency is responsible for ensuring that China's food supply chain is safe, will be replaced by Wang Yong, a senior cabinet official.
Prime Minister Wen has promised to reform the dairy industry.
Mr Li is the first central government official to lose his job over the scandal. His resignation follows the sacking of a number of local officials and the detention of several dozen people involved in the supply of contaminated milk.
Meanwhile, the Chinese Ministry of Agriculture said farmers were dumping milk and killing cattle after companies stopped buying their supplies. It promised subsidies to help farmers.