Fenugreek sprouts are “the most likely connection” between the outbreaks of E. coli O104:H4 in France and Germany, the European Food Safety Authority (EFSA) and the European Centre for Disease Prevention and Control (ECDC) reported Wednesday.

The reports implicate sprouts grown from seeds imported from Egypt by a German company in 2009 and/or 2010. But the health authorities add “there is still much uncertainty about whether this is truly the common cause of all the infections” because so far there is no lab evidence of contaminated seeds.

Based on trace-back investigations, ECDC said the 2009 lot of seeds appears to be linked to the outbreak in France, while the 2010 lot is considered to be suspect in the larger German outbreak. However, this link does not explain a recent case of E. coli O104 in Sweden, reported June 28, in which the case patient had not recently traveled to Germany and cannot recall having eaten sprouts.

“All this is being further investigated,” the ECDC risk-assessment report stated.

A Dusseldorf company, AGA SAAT GMBH, was identified as the seed importer. It apparently supplied seeds to the British seed company Thompson & Morgan, according to the ECDC.  Thompson & Morgan, which has been skeptical that its seeds could have caused the European outbreak, initially said it obtained the seeds from Italy.

In its latest report, EFSA cautions that because fenugreek seeds are often sold within mixes of seeds, cross-contamination could occur during packaging, so consumers in Europe are being advised to thoroughly cook all types of sprouts.