Nearly one quarter of Beijing families have fed their children milk contaminated with the industrial chemical melamine, state press reported Sunday.

In an indication of the scale of the tainted milk scandal that has rocked the country, more than 74,000 of nearly 308,000 households questioned in the capital said their children were fed the products before they were taken off the shelves, the Beijing News reported.

So far at least four infants have died in China, and 53,000 sickened across the country, from drinking milk tainted with melamine. Normally used in making plastics and glue, melamine was added to baby milk formula and other dairy products to make them appear richer in protein.

The paper did not say how many -- if any -- of the fatalities occurred in Beijing.

The scandal broke in early September and has badly tarnished the image of Chinese dairy products, with countries around the world banning or curtailing imports.

Although at least one Chinese dairy firm knew of the problem for months, it did not immediately report it to local government officials. They in turn delayed passing on the news for nearly a month until after the August Beijing Olympics.

According to the Beijing News, hospitals in the capital have reported that 3,458 infants have been hospitalised with kidney stones, the main symptom of ingesting the melamine. More than 211,000 children have had urinary tract examinations at Beijing hospitals and medical clinics since the scandal broke, it added.

China's parliament is currently considering a draft food safety law that aims to prevent any cover-ups by health authorities while making them directly responsible for approving additives in processed foods, Xinhua news agency reported.