Health authorities in France believe sprouted seeds are to blame for the latest outbreak of E. coli which has affected 10 people in Bordeaux.
They say tests showed two of those affected had the same strain of E. coli which earlier caused the deaths of 40 people, mostly in Germany, though there is no suggestion of a link.
Several of the people hospitalised in Bordeaux ate sprouted salad vegetables at a fair at a leisure centre in the Bordeaux suburb of Begres.
French investigators believe the sprouts were grown from seeds imported from Britain, and France halted the sale of three types of seeds linked to a UK company.
The firm, Thompson & Morgan, said it was confident its seeds were not cause of the outbreak.
Britain's Food Standards Agency said no E. coli cases had been reported in the UK.