A Deloitte employee in Beijing recently emailed a PPT file to all employees of the consulting company, exposing the company's alleged accounting violations in China, including turning a blind eye to its clients' abnormal spending and omitting necessary auditing procedures.

The company issued a statement saying it has investigated the complaint but didn't find any evidence to suggest the adequacy of its work was affected. It said further that "We will investigate any doubts we receive". But the company's response has done little to dispel doubts in people's minds.

Malpractices by auditing firms have broad repercussions, as multiple listed companies, and the interests of many investors, might be involved. Deloitte, or any other so-called third-party player in the market, is apparently not in a position to conduct an investigation into its own case.

It is, therefore, absolutely necessary for the China Securities Regulatory Commission, which said "it will launch" a probe into the incident, to do so as soon as possible. If what the whistle-blower has alleged proves to be true, Deloitte is not only violating professional ethics and codes, but also breaking the law.

The timely involvement of the CSRC can help maintain the rigor and reliability of auditing firms as goalkeepers in the market, and strengthen the regulation and supervision of intermediary organizations in the capital market.

For too long, Chinese companies listed in overseas markets have been employing the services of the "big four" auditing firms－namely Deloitte, Ernst& Young, KPMG and PricewaterhouseCoopers－because they are regarded as more authoritative, professional and reliable.

If Deloitte is found guilty of the charge, it should alert market watchdogs to the possibility of the case being only the tip of the iceberg of the malpractices of these big auditing firms. Prestige is not necessarily a guarantee of integrity when it comes to money.

If China wants to boost the development of its capital market, it must follow a zero-tolerance policy toward the bad apples, so as to prevent systemic risks from building up and threatening the country's financial stability. That is also a must for the further opening-up of the country's financial sector.