It is shocking to learn that Husi Food, a Shanghai food distribution company that supplies meat to international fast-food giants, such as McDonald's and KFC, has been supplying unsafe products.

An undercover investigation by reporters found that it had supplied meat products that were up to seven months past their expiration date to McDonald's, KFC and other restaurant chains.

Officials of the Shanghai food and drug authority were also prevented from entering the company until about an hour after staff's arrival at the factory site, arguably long enough for the company to destroy evidence and conceal problematic food items.

The scandal is especially shocking because Husi, a member of the US-based food conglomerate OSI Group, had been seen as a decent market player that abided by the laws and regulations covering food safety. It was even listed by the local district government as a model company for food safety.

If such a star company has been blatantly violating the country's food safety laws and regulations (and worryingly without being caught by either regulators or managers from McDonald's, KFC and other contractors), it is virtually impossible for consumers to have confidence in the whole processed food sector.

The whole nation is watching what the investigation results will be and what punishments will be meted out.

It is essential that the lessons are learnt from this incident, above all, why it was the media, not the watchdogs, that first brought to light the company's actions.

Part of the problem, of course, is that the checks by regulators are made known to corporate managers beforehand. Therefore, they have ample time to prepare for the regulatory checks to ensure their illegal operations, if any, are not uncovered.

Obviously, the regulators should conduct unannounced inspections. Meanwhile, the relevant regulations should be revised to add details as to how the power of regulators in conducting uninformed checks can be guaranteed and how those who block such checks should be punished.

Regulators, given the importance of their work, should also be put under proper scrutiny. If any evidence shows that they have failed in their duties, they should also be punished in accordance with the law.

Such a regulatory change will add to the workload of the country's numerous food safety guardians. But it is indispensable if the country is to improve its food safety.