Organic beansprouts are not to blame for an E coli outbreak that has so far killed 22 people, preliminary test results suggest.

German officials initially feared beansprouts from a farm in Lower Saxony were the source of infections in five German states.

But 23 of 40 samples from the organic farm have tested negative.

Wider tests will now be carried out on samples of older sprouts and packaging from the same farm.

If those tests also prove negative, it will be a major embarrassment for German authorities who had spoken of a clear trail of evidence pointing to the farm.

Earlier, German officials were left red-faced after wrongly blaming Spanish cucumbers for the outbreak which has infected more than 2150 people.

Infections in 12 other countries have all been linked to travel in Germany.

It is now more than two weeks since the Germany informed the European Commission of a significant increase in E.coli patients.

Brussels immediately activated its Rapid Alert System for Food and Feed (RASFF) and Early Warning and Response System (EWRS).

Investigations have since concluded that a Shiga toxin-producing Escherichia coli bacteria is responsible for the outbreak.

In the UK, the Food Standards Agency is reminding consumers of the importance of basic food hygiene practices when preparing food.

“It is a good idea to wash fruit and vegetables before you eat them to ensure that they are clean,” said a statement on the agency website.

Peeling or cooking fruit and vegetables could also remove germs.