A North German farm,Gaertnerhof Bienenbuettel, has been identified as the most likely source of the infection in the E.coli outbreak, that killed 22 people and affected more than 2,200 people, a local media report said.
The farm, producing bean sprouts, located in Uelzen, south of Hamburg, is believed to be the epicenter of the outbreak.
German officials were awaiting results of tests on the farm's produce that would offer more conclusive proof.
The farm has been closed and Germans have been advised to stop eating bean sprouts. The managing director of the farm said on Monday that he was baffled that his bean sprouts were suspected of causing such a devastation.
An emergency meeting is to be held by EU agriculture ministers on Tuesday, to discuss the outbreak and its effect on production.
The agriculture minister for Lower Saxony, Gert Lindemann, said: Further evidence has emerged which points to a plant nursery in Uelzen as the source of the EHEC cases, or at least one of the sources.
Definite proof would depend on test results, but a connection has been found involving all the main outbreaks.
The farm is about 100km (62m) south of Hamburg, and supplies its production to restaurants and markets in the city and neighboring German states.