Locally-grown bean sprouts are the cause of the European E.coli outbreak that has killed 29 people, German experts say.

"It is the sprouts," said Reinhard Burger, the head of Germany's national disease control centre.

He said even though no tests of the sprouts from a farm in Lower Saxony had come back positive, the epidemiological investigation of the pattern of the outbreak had produced enough evidence to draw the conclusion.

He said the Robert Koch Institute was lifting its warning against eating cucumbers, tomatoes and lettuce but keeping the warning in place for the sprouts.

Around 3,000 people have been taken ill, some with serious complications, in the outbreak.

Meanwhile Dutch authorities have recalled red beet sprouts after samples were found to be contaminated with a strain of E.coli apparently less dangerous than the German one.

The Dutch Food Safety Authority said laboratories were still trying to identify the Dutch strain of E.coli, but said there have been no immediate reports of serious illness.

Burger said it is possible that all tainted sprouts have now either being consumed or thrown away, but still warned that the crisis is not over.

"There will be new cases coming up," he said.

Germany has been the epicentre of the outbreak, with 2,808 sickened in Germany, 722 of whom are suffering from a serious complication that can cause kidney failure. In recent days the numbers of people being reported ill have been dropping, but it was not clear whether the epidemic was waning, or people were just successfully shunning vegetables.

The World Health Organisation says 97 others have fallen sick in 12 other European countries, as well as three in the United States.