Chinese milk producer Mengniu Dairy Group said Sunday that inspectors discovered a batch of boxed milk that had excessive levels of a substance known to cause liver cancer.

The discovery was made during a routine inspection by China’s General Administration of Quality Supervision, Inspection and Quarantine, the company said Sunday.

The milk containing carcinogen flavacin M1 was produced in the province of Sichuan. Mengniu Dairy said the questionable milk was immediately sealed and destroyed, and did not reach the market.

The World Health Organization listed flavacin M1, which is found in food mold, as a Class A carcinogen in 1998. Levels of the carcinogen were 140 times higher in the milk batch than that permitted by China.

In the 2008, the company was part of an industrywide scandal after six children died and abou 300,000 became ill from the tainted milk containing the industrial chemical melamine.