The People's Procuratorate of Dongchang district in Tonghua city, Jilin province, has intervened in advance and guided the investigation of a case of disturbing the prevention of infectious disease, CCTV News reported on Thursday.

A person surnamed Ji who owns a health club named Yuanshengpinzhi located in Dongchang on Jan 9 hired a 45-year-old salesman surnamed Lin to hold workshops for the commodities sold in the club, according to a statement from the procuratorate.

Lin was found to be positive for coronavirus during tests conducted on close contacts and was diagnosed as an asymptomatic carrier of COVID-19 on Jan 12.

Then more cases were reported in the city and most of them were in some way connected to Lin.

Lin's marketing and promotional activities caused a virus superspreading event in the city, the statement said. The local public security bureau started the investigation of the case on Jan 17.

As of Wednesday, there were 203 confirmed cases and 81 asymptomatic carriers in the city, which was heavily affected by the recent outbreak.