China's securities regulator has begun to act on initial public offerings (IPOs) violations that occurred last year.

Since September 2012, the China Securities Regulatory Commission (CSRC) has sent eight warning letters to six brokerage firms that failed to disclose information in a timely manner after their newly listed clients reported profit plunges, according to a report from the China Securities Journal.

According to relevant regulations, the CSRC can impose penalties on sponsors and issuers if listed companies post profit declines of 50 percent or greater in the same year that their shares became available for trading on the stock market.

The intensified monitoring efforts are intended to punish sponsors who spice up a company's financial performance to facilitate the process of going public, which may result in a marked profit slump in their annual reports after an IPO is issued.

China's stock market experienced major turbulence last year. The benchmark Shanghai Composite Index dipped to 1,959.77 points on December 3, its lowest reading since 2009.

The poor market has dented the confidence of smaller investors, who attributed their losses to excessive IPOs that allow companies to maliciously take money from the market.

Chinese investors have urged authorities to improve the way new stocks are issued and establish a delisting mechanism. In response, the CSRC has slowed the pace of IPO reviews and rolled out a string of measures to strengthen supervision and crack down on illegal activity.