
Formosa Ha Tinh Steel, part of Formosa Plastics group, is suspected of illegally sending 391 tonnes of cyanide-laced mud to a local company for burial at multiple locations near the plant in Ha Tinh province.
"The cyanide content exceeds the hazard level, so we decided to begin a probe into this case," Bui Dinh Quang, deputy director of the Ha Tinh police department, told local media Tuoi Tre.
The waste was discovered on July 11 after a worker was discovered using an excavator to bury waste at a farm.
The Taiwanese firm admitted in June that a leak at its plant had caused one of Vietnam's worst fish kills in recent history and promised to pay 500 million dollars in compensation, Tuoi Tre said.
- DPA