The BBC asked a pilgrim to take samples from taps which were linked to the Zam Zam well and to buy bottles on sale in Mecca, to compare the water on sale illegally with the genuine source. These showed high levels of nitrate and potentially harmful bacteria, and traces of arsenic at three times the permitted maximum level, just like the illegal water which was purchased in the UK. Dr Yunes Ramadan Teinaz, an environmental health officer who has previously warned about Zam Zam water, said it was “a sensitive matter”. “People see this water as a holy water,” he added. “They find it difficult to accept that it is contaminated but the authorities in Saudi Arabia or in the UK must take action,” he said.