Businesses that fabricate certificates such as university admission letters and sell them online are being targeted after the story of a high school graduate who bought a fake letter for a renowned university to fool his parents made media headlines on Wednesday.

Though it is still unknown where the boy ordered the letter, as the investigation is ongoing, the news has focused public attention on similar products on e-commerce site Taobao.

The internet security department of Alibaba, parent company of Taobao, said on Thursday that the company had punished online manufacturers and retailers involved in fake documents, and had informed authorities.

The company reiterated that it will not tolerate counterfeits and is open to reports from users.

According to the Law of Penalties for Administration of Public Security, anyone who fabricates certificates, documents or seals shall be detained for between 5 and 15 days and fined up to 1,000 yuan ($144).

For more serious cases, the Criminal Law stipulates that fabricators face jail terms up to three years.

The graduate, surnamed Cao, from Zhanjiang, Guangdong province, scored 235 points out of 750 in this year's national college entrance exam. He told his family he had scored 702, according to media reports.

To convince his parents, who were busy with their fishery business and ignored his daily academic performance, the boy spent 3,000 yuan ordering a fake admission letter for prestigious Tsinghua University in Beijing, and said he was admitted as an artificial intelligence major.

Later, his neighbors figured out the misuse of some Chinese characters in the admission letter and discovered the lie.

The local police bureau said that the student had not committed a crime as he had only fabricated one admission letter, and would likely be given a verbal warning.

Until Wednesday, fake admission letters were still seen being sold on Taobao, according to a report by The Paper.cn.

For example, one capable online shop could design dozens of universities' admission letters including for Northeast Normal University in Changchun, Jilin province, and Shanghai Jiao Tong University.

Purchasers could get a letter with their name, student number and a fake seal of the university within a week, the report said.

However, on Friday, Taobao showed no search results for admission letters or similar products such as diplomas.

Yu Ping, a commentator with Red Star News based in Chengdu, Sichuan province, said that some students bought fake letters to please parents, while in other cases people use them to fake identity and commit fraud, which does a lot more harm to society.

Liu Lin, a lawyer from Beijing Shuangli Law Firm, said those who run businesses should not only guarantee the quality of their products but had better confirm how they will be used.

"Under no circumstances is selling fake admission letters or similar products in consumers' interests, nor is it ethical," Liu said.