Muslims are being warned about potentially lethal fake holy water believed to be on sale in Tooting.
Demand for holy Zam Zam water increases as Muslims prepare to celebrate the month of Ramadan, which begins on or around August 22.
But today Wandsworth Council issued a public health alert today after tests revealed a consignment of the fake water contained twice the levels of permitted arsenic and three times the level of nitrates.
Consuming the water could be potentially lethal for children and pregnant women, a council spokesman said.
He said: “Arsenic is a deadly toxin and can be ingested into the body through contact with skin.
"In high doses it can lead to multi-organ failure, brain damage and death. Lower doses can cause cancer.
"Nitrate poisoning is especially harmful to babies and pregnant women, and interferes with the way that blood carries oxygen around the body. It can also lead to brain damage and death.”
Real Zam Zam water comes from the Well of Zam Zam in Mecca, the holiest place in Islamic religion.
The Saudi Arabian Government prohibited the commercial export of Zam Zam Water from the kingdom and under Saudi law the water cannot be lawfully sold overseas.
But there is a thriving trade in fake Zam Zam water globally.
Genuine Zam Zam water is brought into UK by pilgrims returning from Mecca.
If any member of the public becomes aware of the water being offered for sale in the borough they should contact the council's food safety team on 020 8871 6166.