The French Interior Ministry said this evening that traces of the deadly toxin ricin have been found in the Gare de Lyon railway station in Paris.
A spokesman told Reuters that two small flasks containing traces of the poison were discovered in a left luggage depot at the mainline railway station which serves the south of France.
In January, British anti-terrorist police arrested several people in connection with the alleged discovery of ricin in a tiny north London flat.
Ricin, one of the deadliest naturally occurring poisons, is derived from castor plant beans, which are grown worldwide to produce castor oil.
The chemical, which is many times more deadly than cyanide, is considered a likely bio-warfare agent and is on the Center for Disease Control and Prevention's "B" list of agents - considered a moderate threat.