The farmers were contracted to dispose of dead swine on a farm in the southeastern province of Fujian but instead sold the meat for human consumption, the Global Times newspaper said.
More than 40 tonnes were sold, worth some three million yuan (USD 490,000), the newspaper added.
Animal disease investigators found a "pseudo-rabies virus" -- which is related to the herpes virus, rather than rabies -- and also the virus that causes blue ear disease, "which likely killed the pigs", the report said.
A truck driver and guard drafted in by the trio are also facing charges, according to a statement from the ministry of public security. Three butchers hired to process the meat remain at large, the Global Times report said.
Food safety is a major issue in China following a string of scandals, including the discovery in March of thousands of dead pigs floating down a Shanghai river.
In another recent incident, US fast food giant KFC was hit by controversy after revealing some Chinese suppliers provided chicken with high levels of antibiotics, in what appeared to be an industry-wide practice.
One of China's worst food scandals hit in 2008 when the industrial chemical melamine was found to have been illegally added to dairy products, killing at least six babies and making 300,000 people ill.
