Chinese authorities are hunting 300 people suspected of illegally selling deadly, spoiled vaccines, in what could be the country's biggest case of its kind.
Late on Friday authorities issued a public notice of the identities of the suspects, who are thought to have been involved a vaccine trading ring worth as much as 570 million yuan ($88 million), state media reported.
The authorities called on the public to help track down the dealers involved, the reports said.
According to Xinhua News Agency, the suspects sold compromised vaccines, which were neither adequately refrigerated for storage nor transported in approved conditions, to hospitals and disease control centers in at least 24 provinces and municipalities, including Beijing, where they were used over a number of years
The vaccines had the potential to cause disability or death, Xinhua reported.
The reports said that although the case was not made public until Friday, the illegal operation was first discovered in April 2015.
Since then, the police had made over 20 raids across the country to confiscate unsafe products and had arrested a former doctor only identified by her surname, Pang, as well as her daughter, a medical school graduate, in eastern China's Shandong Province, the reports said.
The women had profited from the illegal sale of vaccines since early 2010, the State Public Security Bureau alleged.
The duo are accused of purchasing 25 types of vaccines from more than 100 pharmaceutical salesmen, both licensed and unlicensed, then selling them on to illegal agents as well as local medical facilities at higher prices.
So far, authorities have been unable to work out precisely what quantity of compromised vaccine entered the market, media reports said.
The vaccines the suspects allegedly sold included ones used against chicken pox, rabies, meningitis and hepatitis A, none of which are mandatory injections in the mainland.
Thepaper.com, the digital news outlet that first broke the story, reported that Pang, 47, had worked as a doctor at a public hospital but in 2009 was given a three-year prison sentence, suspended for five years, after she was convicted of illegally selling vaccines worth almost five million yuan ($763,358).
Angry Chinese asked on social media why the case was only revealed almost a year after police had solid evidence that unsafe vaccines had been widely used, and how the justice system had allegedly allowed the former doctor to commit the same crime twice.
China is one of the world's largest pharmaceutical markets but also the biggest producer of counterfeit pharmaceuticals, according to a report by the London-based International Policy Network.
Plagued by drug scandals, Beijing has ramped up its policing of the drug sector and called on hospitals and clinics to improve transparency on their drug purchases.
However, the crackdown, which includes more severe punishments for the production and sale of fake or substandard pharmaceuticals, so far appears to have had little impact.