Drug authorities in Shanghai claim to have busted the city's biggest underground pharmaceutical racket, arresting 18 people from several gangs believed to have dealt in more than 90 million yuan of illicit medicines. The Shanghai Food and Drug Administration said on Monday the suspects had been operating since 2002. Inspectors seized more than 1,000 kinds of illegal medicine valued at nearly 3 million yuan. Authorities say the dealers bought surplus or expired drugs from state-owned units and individuals and repackaged and distributed them in less developed regions including Anhui , Zhejiang , Henan and Sichuan . Most buyers were rural residents who did not have access to regular pharmacies or clinics and uninsured migrant workers in cities who could not afford high medical fees, said a public health expert from Shanghai's Jiaotong University Medical School. The administration said several of the suspects used the profits to buy property and cars in Shanghai. The drug administration called on the public to refrain from selling excess medications to street dealers. Investigators found some Shanghai citizens, especially those affiliated with SOEs and government departments who paid almost nothing for their medical insurance, would use their insurance quota to buy drugs from public hospitals and sell them to drug scalpers for a profit.