A sip of coffee might be dangerous these days, especially if you are in the United Kingdom. 

BBC consumer-affairs program, Watchdog, discovered that the three biggest coffee chains in the UK, Starbucks, Costa and Caffe Nero, were found to contain bacteria from feces in ice they used for cold drinks.

For Starbucks and Caffe Nero, three out of 10 samples of collected ice were contaminated by fecal bacteria, and the result for Costa was seven out of 10, according to the investigation.  

A cup of hot coffee from Costa. /VCG Photo

Tony Lewis, head of policy at the Chartered Institute of Environmental Health, told the BBC that the amount of bacteria found at these coffee giants was "concerning" and these types of bacteria can cause disease in humans.

“It is extremely important to us that all our stores operate to high standards of hygiene at all times, and we take it very seriously when any store fails to meet these standards,” a spokesperson of Costa said in a statement to MarketWatch. 

“We adopt industry standard cleaning processes across all our stores, in line with the Food Standard Agency’s advice. Following these results we have taken immediate action to update our ice handling procedures,” the spokesperson added.

A cup of hot coffee in a Caffe Nero branch. /VCG Photo

After the findings were revealed, Starbucks and Caffe Nero said they will be conducting their own investigations into the matter. 

Meanwhile, Starbucks China told finance.china.com.cn that they haven’t received any complaints from customers on the issue nor a notification of an investigation from the head office.