Harles and Jentzsch, the company accused of supplying dioxin-contaminated fat to the animal-feed industry in Germany, filed in court for insolvency on Wednesday.

According to Deutchland Online, the court will have to decide if the conditions for insolvency apply. The company must show it is unable to pay its bills or is saddled with too much debt.

The company, based in Uetersen, north-west of Hamburg, is under investigation by prosecutors and could also potentially face vast civil claims from 5,000 German farms that were closed down during the dioxin scare.

Harles and Jentzsch has been accused of supplying around 3,000 tons of cheap fat intended for industrial use as an ingredient for feed intended for chickens and pigs.

Some 400 farms are still closed.

The agriculture ministry of the state of Lower Saxony, where most of the closed farms are, has said that it is likely that contaminated pork may have been on sale in stores. Animals from a farm in whose pigs high levels of dioxin had been found were known to have been sent for slaughter in December before the closures were imposed.

The federal agriculture minister, Ilse Aigner, called on Lower Saxony to check urgently whether contaminated pork had entered the market, in order to ensure that any pork still on sale could be removed from the shelves.

China has followed South Korea and banned the import of German pork and eggs.

The government has repeatedly assured the public that there is no danger from the dioxin-contaminated food. Small amounts of dioxin, which is an industrial waste product, are believed to cause no harm, but the body collects dioxin throughout life, and it is suspected of causing cancer in higher doses.