After days of recriminations that threatened new inter-European trade wars, the German authorities conceded contaminated Spanish cucumbers are not to blame for a mystery illness which has claimed the lives of 16 people and infected more than 1200 others.

It has emerged that many more women than men are falling ill in what is now one of the world's most deadly E.coli outbreaks. The search to find the source of the infection was stepped up, although scientists said vegetables such as spinach or salads remained a likely cause because of animal manure used as fertiliser.

Russia meanwhile threatened to extend its ban on German and Spanish produce to include the whole of the European Union, as growers demanded hundreds of millions of euros to compensate them for the collapse of cucumber, tomato and lettuce sales.

German State Agriculture Secretary Robert Kloos admitted tests revealed Spanish cucumbers did not carry the deadly bacteria strain - confirming earlier investigations carried out on three sites in Spain.

"Germany recognises that the Spanish cucumbers are not the cause," he said at an EU farm ministers meeting in Hungary.

Spanish Agriculture Minister Rosa Aguilar criticised the German response. "Germany accused Spain of being responsible for the E.coli contamination in Germany, and it did it with no proof, causing irreparable damage to the Spanish production sector," she said.

Denmark, the Czech Republic, Luxembourg, Hungary, Sweden and Belgium have stopped importing Spanish produce while Germany has told people to stop eating it.

The disease has been identified as hemolytic-uremic syndrome, a serious complication of a type of E.coli which affects the blood, nervous system and causes kidney failure. Other victims, all of whom had returned from Germany, have been confirmed in Spain, Denmark, France, Netherlands, the Czech Republic and Sweden.

WHEN E COLI TURNS DEADLY

E.Coli are bacteria that occur naturally in the intestines of humans and all warm-blooded animals. Most strains are harmless but some, such as the O104 strain implicated in the German outbreak, produce toxins that can cause serious illness.

Cattle can carry these toxin-producing strains of E.coli in their intestines without showing any symptoms of illness. If their manure is then used as a fertiliser there is a risk that the vegetables may become contaminated. Infection can be avoided by washing all vegetables.

- Independent