High arsenic levels have been found in bottled water claiming to come from a sacred Muslim site, the food watchdog said today.

The Food Standards Agency is warning consumers not to drink products labelled as Zam Zam water.

Tests carried out by Leicester City Council this month revealed high arsenic levels in the drink.

It follows tests last year which showed arsenic at almost three times the permitted level in bottles of Zam Zam on sale in the UK.

Arsenic can increase the risk of cancer in some cases, according the Food Standards Agency.

The Agency has written to local councils asking them to clamp down on the sale of Zam Zam water.

"Genuine Zam Zam water, which is sacred to Muslims, comes from a specific source in Saudi Arabia and cannot legally be exported from that country for commercial sale," the FSA said in a statement.

"Therefore, any product found in the shops would have an uncertain origin and could pose a safety risk."

The warnings do not apply to genuine Zam Zam water, which comes from Saudi Arabia and can be brought into the UK as a "personal import" by returning pilgrims.

Copyright Press Association 2006.