Thames Water has sent samples of water for lab testing after dozens of people reported becoming unwell with stomach cramps, vomiting and diarrhoea in south-east London. Earlier this month, unsafe drinking water led to more than 100 cases of a waterborne disease in Devon, with people asked to boil their water because of contamination fears. After cryptosporidium, a disease that can cause symptoms such as diarrhoea and vomiting, was detected in the water supply in the Brixham area of Devon 10 days ago, 17,000 households and businesses were told by South West Water not to use their tap water for drinking without boiling and cooling it first. Now residents in Beckenham have reported being struck by a stomach bug which is causing days of vomiting and diarrhoea. They include a four-year-old boy suffering days of vomiting, and an adult woman who was so unwell she went to hospital with stomach pain, vomiting and dehydration. Katie Cox, a TV producer who lives in the area, said: “I was unwell two weeks ago with what I thought was a stomach bug. It was a good week before I was able to eat again properly. Since then, the South West Water contamination has come to light and I became concerned that maybe there is something in our water.” Whole families have reported becoming unwell, and fear it may be caused by a bug in the water. After reporting the issue to Thames Water, people who have been unwell said technicians came to take samples of their tap water. Thames Water confirmed its technicians collected samples, which have been sent for laboratory analysis. Thames Water said: “Our technicians collected samples from a property in the area on Tuesday 22 May following customers contacting the business. Initial on site testing carried out by our accredited technician did not indicate an aesthetic issue with the water, further samples were also collected for laboratory analysis and results showed no concerns. “Customers can find information about their water supply by inputting their postcode on our website. Should anyone be concerned about their tap water, we’d encourage them to contact us.” A spokesperson said: “We take the quality of our water extremely seriously – it is the highest quality drinking water in the world – and since 2010 more than 99.95% of tests taken from customers’ taps met the standard required by UK and European legislation. Every year, we carry out more than 500,000 tests.” Labour’s shadow environment secretary, Steve Reed, said: “Our water industry is broken. Just days ago, a parasite outbreak was making people sick in Devon, now [Beckenham’s] drinking water may not be safe to drink.” In Devon, South West Water said on 14 May that the water was safe to drink before reversing this advice a day later. The business said data from tests showed treated water leaving its treatment works was not contaminated, but further tests overnight found small traces of cryptosporidium. In Brixham, 2,500 properties remain under boil tap water notices as the system continues to be flushed, and there has been no date given to those properties for when the water will be safe to drink again. David Harris, South West Water’s drought and resilience director, said: “We will not lift that boil water notice until it is safe to do so.”