Chinese food and drug makers struggling in a declining economy could be tempted to cut corners and ignore quality standards, a senior Chinese official warned as the country awaits court verdicts in a tainted milk scandal.

China has been rocked by a number of scandals in recent years involving unsafe food and drugs which have sometimes killed people and prompted global recalls of Chinese-made goods.

At least six children last year died from drinking milk formula adulterated with melamine, an industrial compound used to cheat nutrition tests, and more than 290,000 fell ill with kidney stones. China has put on trial a number of company officials and farmers accused of producing and selling the toxic milk.

Shao Mingli, a senior official from China's food and drug safety watchdog, said that the country was on "high alert" as the impact of the financial crisis began to hit home, Xinhua news agency quoted him as saying late on Tuesday.

"Some enterprises might conduct production in violation of standards and regulations in an attempt to ease their financial burdens," Shao said.

"On the other hand, conflicts and disputes arising from some companies' regrouping or merger and acquisition might impact production and quality management," the official added, calling for tighter supervision of all levels of the supply chain.

The watchdog had dealt with 297,500 cases of "illegal drugs and medical equipment" with a value of about 600 million yuan ($88 million) last year, Xinhua said, in an indication of the seriousness of the problem.

The report comes amid an investigation into a health scare involving a foreign brand of dog food, which local media have linked to the deaths of dozens of pets.

The China Daily on Tuesday said that at least 30 dogs had died from liver complications after eating a brand of dog food which the state newspaper said was tainted with aflatoxin.

The paper quoted vets who said a number of dogs had been diagnosed with liver damage after eating the pet food, and a local supplier that had stopped selling it.

But China's General Administration of Quality Supervision, Inspection and Quarantine said it had neither approved the food for import, nor had border quarantine units ever allowed its import, Xinhua said, casting doubt over the product's origins.

In 2007, pet food made with Chinese ingredients tainted with melamine killed a number of dogs and cats in the United States.