Gastroenteritis caused by bottled water has affected 3,166 people in Catalonia, according to the regional health department.
The water was drawn from a natural spring called Arinsal, in the principality of Andorra between Spain and France. It was distributed in Catalonia by a company named Eden.
Eden notes that it receives the sealed bottles from Andorra and merely distributes them.
Health authorities are calling all businesses that sold the product in a bid to tally a final number of affected customers. Because the gastroenteritis had mild effects, not all patients went to the doctor, department sources said.
The first tests conducted on patient samples show the presence of a norovirus, a microorganism that is responsible for half of all common gastroenteritis. It is present in animal droppings, which can contaminate the water.