China has launched an investigation into internet search giant Baidu following the death of a student, who tried a cancer therapy which he found through an online ad. The Cyberspace Administration of China (CAC) along with the State Administration of Industry and Commerce, National Health and Family Planning Commission are looking into the "Wei Zexi incident".

Wei, a 21-year-old student from Xidian University in China's Shaanxi Province, was diagnosed with a rare form of cancer, synovial sarcoma, in 2014 and was undergoing treatment for cancer. Wei and his family found a treatment offered by the Beijing Armed Police Corps No 2 Hospital through Baidu search.

Wei received radiation and chemotherapy, following which his family turned to an alternative treatment found via Baidu that cost 200,000 yuan ($31,000) at the Beijing hospital, which was unsuccessful.

A Baidu spokesperson in a statement said: "We deeply regret the death of Zeix. May Zeix rest in peace." The company says it will cooperate with the investigation. It also committed to providing "a safe and trustworthy search experience for our users". The statement added that Baidu "will give no quarter to fake informational or illegal activities online".

The official Chinese news agency Xinhua accused Baidu of abusing its search for its profit. It said: "Making money by allowing companies to pay for better search placement is to put a good tool in the hands of interest-seekers with bad intentions."

Wei's parents in a statement said they don't have plans to take the matter to court. "We harbour no hatred for Baidu or the hospital," they said.

Baidu, in its response, said it does not work with substandard private hospitals and has a team for monitoring medical advertisements that comply with Chinese laws. It also has a set of procedures and requirements for safe advertising, suggests a Wall Street Journal report.

Baidu is China's major search engine with a market share of about 80%. Like other search engines, it generates the lion's share of its revenue from ads. It generated 94% revenue through online ads in the first quarter of 2016. The company at its recent earnings call said medical care was one of its top areas.

In January, Baidu was widely criticised after it sold the management rights to an online forum related to haemophilia to a company whose site was filled with questionable information. Baidu, after acknowledging its mistake, said it would stop the practice of making money from patients.