A Chinese herbal drugmaker is under public scrutiny after an online article went viral accusing the company of misleading advertising of a cancer treatment that was linked to the death of a 4-year-old girl in 2015.

Tianjin-based Quanjian Nature Medicine Technology Development Co. Ltd. faced a public outcry after Dingxiangyuan, an online health information service, published an article Dec. 25 accusing the company of using false advertising to cheat consumers.

The article linked Quanjian to the death of a girl who suffered from cancer and missed the opportunity of cure by taking therapy provided by Quanjian. The drugmaker denied any wrongdoing and demanded an apology from Dingxiangyuan, which refused.

Quanjian described itself as China’s biggest direct seller of herbal-based medicine and health-care products. Public records showed that the company’s 2017 revenue totaled more than 1 billion yuan ($145 million) with net profit of 128 million yuan.

A Caixin search of health-care product registration records found that only 13 among more than 100 products sold by Quanjian have proper registration records. Quanjian declined to comment.

The controversy surrounding Quanjian prompted the state market regulator to issue a notice Wednesday tightening requirements on marketing activities of direct sellers of health-care products.

A previous version of this story misstated the company’s name as Quanjian Group. It is Quanjian Nature Medicine Technology Development Co. Ltd., the major unit of Quanjian Group.