How do you spot ‘fake’ water?

This item is from BBC news on Wednesday, 3 September 2008:
Fake sacred water ‘poses danger’

Muslims observing Ramadan have been urged to avoid bottled water which may contain high levels of poison arsenic. Sacred Zam Zam water originates from Saudi Arabia and cannot be exported from the country for commercial sale. Zam Zam is traditionally drunk by pilgrims for its healing properties and during the holy period of Ramadan. Environmental health officers in Luton have warned that bottles for sale that are labelled as Zam Zam water are of unknown origin and pose a risk. Joan Bailey, of Luton Borough Council, said: “In previous years this product has been on sale in Luton and anyone who has bought the product is being advised to throw it away. “As we can’t trace the origin of this water, it poses a great risk to anyone who consumes it.”

This batch, photographed in Malaysia, is by thefunks on Flickr.