About 3,000 German farms were given the go-ahead to resume making food deliveries as an investigation continues into how dioxin got into animal feed and eggs, the BBC reported Sunday.

But although health experts say the dioxin found in German eggs was at levels too low to pose a threat to human health, the levels nevertheless exceeded government-set limits and have touched off a scare that Germany is still trying to contain.

Deliveries had been halted from about 4,700 German farms after the potentially carcinogenic chemical was found in eggs.  Investigators then discovered that fatty acids meant for industrial use had instead been sold to some 25 animal feed makers.

Last week, Britain’s Food Standards Agency warned consumers that some dioxin-tainted eggs might have been mixed with noncontaminated eggs to make liquid egg products used commercially in mayonnaise and cakes.

As a precautionary measure, the Tesco supermarket chain in Ireland announced it was taking a variety of cakes off its shelves, according to a report in the Irish Times.

South Korean and Slovakia said they were halting German meat and poultry imports, which brought protests from the European Commission on Saturday that there were no grounds for such a ban.

But on Sunday the EU Commission acknowledged that three chickens out of several samples it had tested showed dioxin concentrations of twice the legal limit, a British newspaper, the Telegraph, reported.

Also on Sunday, Danish authorities said they had been alerted by the European Union foods safety system, the Rapid Alert System for Food and Feed, that some of the German feed had been sold in Denmark.  But the Danes said it went only to breeder hens.

Germany does not export poultry and eggs to the U.S., however the U.S. Department of Agriculture said on Friday it was working with Germany to determine if any affected pork products might have gone to the U.S. 

The feed manufacturer, Harles & Jentzsch, said it had mixed waste from biofuel production into animal feed assuming it was safe.  The company initially said it was a one-time mistake, but on Friday the German agriculture ministry said it had evidence the manufacturer might have begun shipping the dioxin-tainted fat in March, despite tests that should have alerted it to the problem.