The Dutch authorities on Friday re-opened 96 livestock farms out of nearly 200 it had sealed off as a precaution after discovering cancer-causing dioxin in animal feed.

“We decided to reopen 96 farms today after the first results showed no contamination of meat. These are mainly pig farms,” a farm ministry spokeswoman said.

Earlier results showed contaminated milk in only two of the closed farms, the ministry has said.

The dioxin scare has spread to Germany, Belgium, France and Spain in the past two weeks but the European Union and Dutch health officials have ruled out any risk to public health, saying contaminated products had not reached consumers.

Some 100 Dutch pig, cattle, sheep and goat farms will remain shut until all tests are completed in the second half of next week, the ministry said.

Dutch authorities have said that German-made clay used for sorting potatoes was the reason for the dioxin contamination of animal feed made using potato peelings.

The clay was bought by 10 Dutch potato companies and was also shipped to companies in France and Belgium, the ministry has said.

It has said that two cows from one of the affected Dutch farms were exported to Spain.

Dutch authorities have also found that contaminated feed had been exported to Belgium and Germany, which has led to the temporary closure of eight livestock farms in Belgium and five in Germany.

Dioxins are one of a number of toxic chemicals that originate in pesticides or industrial processes, seep into rivers and lakes and build up in the flesh of fish and animals.