The German government has launched an investigation after it was discovered that around 100 organic farms have been feeding chickens wheat containing the banned herbicide Nitrofen.

The agriculture ministry in Lower Saxony, where the tainted wheat was first discovered, has claimed that contaminated meat and eggs have already been sold and consumed. The affair is particularly scandalous in Germany, as the country considers itself to be at the forefront of European organic production. It is believed that a Lower Saxony animal feed company has already sold the wheat across the country.

Nitrofen is banned in the EU because of concerns that it is carcinogenic.

By Keith Nuthall, correspondent