China's Internet regulator said on Monday it will send a team to investigate Baidu Inc over the death of a university student who used the Chinese search engine to look for treatment for his cancer.
Wei Zexi, 21, died last month of a rare form of cancer.
He had look online via Baidu for the best place for treatment, finding a department under the Second Hospital of Beijing Armed Police Corps which offered an experimental form of treatment that ultimately failed, according to state media.
Before dying, Wei accused Baidu online of promoting false medical information, as well as the hospital for misleading advertising in claiming a high success rate for the treatment, state radio said.
"Wei's family says they trusted the treatment because it was promoted by one of the military hospitals which are considered credible, and the attending doctor had appeared on many mainstream media platforms," state radio said.
The regulator said in a short statement that Wei's case had attracted widespread attention on the Internet.
It, the health ministry and State Administration for Industry and Commerce would investigate Baidu and "handle it in accordance with the law" and publicise its findings, it said.
Baidu said in a statement it deeply regretted Wei's death and sent its condolences to his family.
"Baidu strives to provide a safe and trustworthy search experience for our users, and have launched an immediate investigation of the matter," it said.
The company added it welcomed the investigation and would fully cooperate.
Baidu shares dropped six percent in early New York trading.
Chinese Internet portal Sina, citing unidentified sources within Baidu, said the regulator had also asked to speak to Baidu CEO, Robin Li, although it was not clear what the subject might be.
A Baidu spokeswoman said the company had no additional comment.
Baidu has been in trouble before on medical related issues.
This year, it was criticised for selling management rights for an online forum related to haemophilia to an unlicensed private hospital, which then used the platform for self-promotion and which also deleted comments that challenged its credentials, the official Xinhua news agency said.
In 2010, China's state-run television accused Baidu of promoting counterfeit drugs through its search engine.