The national environmental watchdog has started a probe into the alleged illegal discharge of untreated sewage and toxic waste into a river and lake in Xinyu city, Jiangxi province.

The Ministry of Environmental Protection said on Thursday that it suspects Yichun Zhong'an Industrial Co, a chemical plant, discharged the pollutants on April 3.

The waste that spewed into the Yuanhe River, which links to Xiannyu Lake, contained toxic chemicals including arsenic, thallium and cadmium.