The State Administration for Industry and Commerce (SAIC), in a report published on its website on Wednesday, said many products sold on Alibaba's e-commerce websites and services infringed upon trademarks, were substandard or fake, were banned or endangered public security.
The report was later removed from the main page of the SAIC website. (www.saic.gov.cn)
An Alibaba spokesman declined to provide immediate comment.
SAIC said the report summarised a July 16, 2014, meeting between government business regulators and Alibaba, and that it had delayed releasing the report to avoid affecting the e-commerce firm's initial public offering, which took place in September.
SAIC did not elaborate. Alibaba, which raised a record-setting $25 billion from its New York IPO, is due to release its quarterly results on Thursday.
"Alibaba Group has long paid insufficient attention to the illegal business activities on Alibaba platforms," the SAIC report said. Alibaba "let that abscess fester until it became a danger", it added.
The report said Alibaba officials, for their part, pledged during the July meeting to take the necessary steps to rectify the problems. The SAIC has a broad supervisory role over online trading platforms and business in China.
Alibaba, which until a few years ago was on a U.S. list of "notorious markets" for intellectual property infringement, has fought hard to tackle counterfeit products to keep its reputation from being tarnished in the run-up to the IPO, th eworld's biggest ever listing.