A Shanghai-listed company suspended trading of its shares on Tuesday in the wake of the death of 21-year-old cancer patient Wei Zexi.
The company, VCANBIO Cell & Gene Engineering Corp, issued a public statement in March on the acquisition of 100 per cent of the equity in Shanghai Claison Bio-tech Co, with investment of 1.1 billion yuan (S$230 million).
Clasion provided immunotherapy technology services for the Second Hospital of the Beijing Armed Police Corps, where Wei received immunotherapy treatment.
Wei learned about the treatment from search engine giant Baidu, but died last month from a rare form of cancer.
Since news of his death broke, it has been impossible to access Clasion's website, which is displaying the words "coming soon".
Asked if there was a connection between Clasion and the hospital, VCANBIO's general manager Wu Mingyuan said it was not possible to give a response at present and the company would release a statement later.
Clasion's main business involves research and development of cellular immunotherapy and providing technical services for medical institutions.
The company's technical services for this therapy include using a patient's own cells to fight cancer, and the controversy over Wei's death centres on such therapy.
Earlier, VCANBIO said it intends to acquire Kangxin Hospital Investment and Management Co. This hospital manages the domain name of the tumour diagnosis and biological treatment centre of the Second Hospital of the Beijing Armed Police Corps.
Clasion and Kangxin are both controlled by Chen Xinxi and Chen Xinxian from Putian, Fujian province.
Another listed company saw its stocks plunge on Tuesday.
Shares in Hua Xia Healthcare Holdings dropped by 13 per cent to close at 53 Hong Kong cents ($0.06). The company is controlled by Weng Jiajin, the son of Putian businessman Weng Guoliang.
Ji Xuwo, a healthcare analyst at Orient Securities in Beijing, said: "This case is expected to accelerate the launch of standardized regulations on the cellular therapy industry in China. The sector lacks supervision and quality control in specific clinical applications.
"The private medical care system in China will in future focus on medical quality, and only those companies that can provide value for patients can achieve growth."