Milk contaminated with cancer-causing aflatoxin has been found in a second consignment, the food safety body NVWA said on Wednesday. The milk came from two dairy farms, the NVWA said.
Production at the farms, which were not named, has been halted while experts try to determine the source of the contamination.
Last month, the NVWA said a consignment of contaminated milk had been found on two other dairy farms at the end of last year. Those farms have since been given the green light to resume production.
Dutch farms are also on the look-out for animal feed which has been contaminated with aflatoxin. The substance is produced by fungus that grows on hay or grains. It shows up in the milk of animals that ingest it.
Earlier this week, it emerged contaminated animal feed from Serbia had been discovered in the Netherlands at five pig farms. Three other farms had also received contaminated feed from Romania.
The feed contains corn contaminated with aflatoxin. It was first discovered in Germany last Friday, where the food safety authority said a possible 6,500 farms are involved.
It is not clear from the Dutch media reports if there is a link between the animal feed and the dairy cases.