China's food quality regulator has confirmed that it didn't find more excessive levels of cancer-causing substance aflatoxin in milk.

The General Administration of Quality Supervision, Inspection & Quarantine had collected samples of milk from dairy products suppliers Mengniu, Yili Industrial Group Co, Beijing Sangyuan Foods Co, Bright Dairy & Food Co and Nestle SA to determine if milk contained excess toxins.

Earlier, the Chinese food safety watchdog had found high levels of aflatoxin in milk supplied by China's biggest dairy products manufacturer Mengniu.

Aflatoxin, which occurs in the environment and is produced by some common sorts of fungi, is a highly toxic substance that raises the risk of different types of cancer, such as liver cancer.

Public concern was triggered earlier this week after China's food safety watchdog announced that milk supplied by Mengniu's Sichuan plant had higher levels of aflatoxin than prescribed standards.

It was not the first time when milk products were found containing toxins in excess of standards. In 2008, more than six children died and as many as 300,000 became sick in many provinces of China after drinking powdered milk that was found containing melamine, which was added to give low-quality milk high protein readings.