A BBC Watchdog investigation of iced water from the three major coffee chains Costa, Starbucks and Caffe Nero found faecal coliform bacteria in samples.

An undercover investigation revealed that iced water obtained from high street outlets Caffè Nero, Starbucks and Costa Coffee all contained faecal coliform bacteria, with a positive test found for seven out of 10 samples from Costa and three out of 10 samples from the other two chains. Cleanliness of tables, trays and high chairs at the chains was also tested at 30 branches.

The faecal contamination is a clear indicator of poor hygiene and it is most likely the ice was contaminated by unclean hands touching the ice or possibly from the use of unclean equipment.

Although it is a small sample size, it does emphasis how essential good hygiene and cleaning are in places that may be overlooked by the food business such as ice machines.

All three chains have responded to the findings by the BBC’s Watchdog programme, saying that they are taking steps in the matter and environmental health officials for the areas have been notified.