Number 10 has been forced to clarify after Boris Johnson suggested that the government would be able to track the rate of coronavirus by testing the water supply.
Speaking in the House of Commons the Prime Minister spoke about strengthening lockdown measures in a particular area due to a local "flare up".
But his comments about detecting the deadly virus "in the water supply" confused and scared many. His aides rushed to insist that he was referring to waste water rather than the fresh water coming out of people's taps.
Mr Johnson told MPs: "The intention is that the covid alert system in time will be sufficiently sensitive and flexible so as to detect local flare ups, so that if for example the Covid is detected in the water supply of a