Chinese authorities shut down a dairy in Shanghai and arrested three of its executives after tests found some of its milk products were tainted with the same industrial chemical at the center of a milk safety scandal more than a year ago, state media said BEIJING (AP) — Chinese authorities shut down a dairy in Shanghai and arrested three of its executives after tests found some of its milk products were tainted with the same industrial chemical at the center of a milk safety scandal more than a year ago, state media said Friday.

The Shanghai Daily newspaper said authorities found that Shanghai Panda Dairy Co. Ltd. was producing milk powder and condensed milk with unacceptably high levels of melamine, which can cause kidney stones and kidney failure.

It said eight batches of contaminated milk powder and condensed milk were found and would be destroyed.

Authorities revoked Shanghai Panda's business and food production licenses and arrested its corporate representative, general manager and deputy general manager, the report said.

Calls to the company rang unanswered and the Shanghai municipal public security bureau was shut on New Year's Day, a public holiday in China.

At least six children died in 2008 after drinking contaminated baby formula and more than 300,000 were sickened in one of the country's worst food safety crises. The scandal exposed the widespread practice of adding melamine, normally used in the manufacture of plastics and fertilizer, to watered-down milk to increase profits and fool inspectors testing for protein.

Last month, police detained three people suspected of selling tons of melamine-tainted milk powder in northern Shaanxi province. Weeks earlier, China executed a dairy farmer and a milk salesman for involvement in the 2008 scandal.

The cases underscore the challenges China faces in improving food safety, despite the enactment last year of a tough food safety law promising harsher penalties for makers of tainted products. China continues to have trouble regulating countless small enterprises and illegally run operations that are often blamed for introducing illegal chemicals and food additives.