Lab tests carried out by BBC One’s consumer series Watchdog showed samples from drinks at Costa, Starbucks, and Caffè Nero reportedly found to be contaminated.
Faecal coliforms, which contain disease-causing pathogens, were present in 7 out of 10 ice samples in Costa, 3 out 10 in Caffè Nero and 3 out of 10 in Starbucks, the BBC said.
Tony Lewis, Chartered Institute of Environmental Health, told the programme: “The level of contamination of faecal bacteria concerns me a great deal.
“The bacteria found are opportunistic pathogens – the source of human disease.
“These should not be present at any level – never mind the significant numbers found.”
Throughout the tests, cleanliness of tables, trays, and high chairs at the chains was also checked at 30 branches.
A spokesman for Starbucks said it takes hygiene ‘extremely seriously’ and ‘nothing is more important’ than customer safety.
“We have moved quickly to conduct our own investigation into the claims about the stores,” he added.
“All employees nationwide have received updated training on our high standards of hygiene including ice handling.”
Costa said: “We were disappointed with the findings, especially as these stores are all rated ‘very good’ with a the top hygiene rating of five.
“Following these results we took immediate action to review our food safety procedures and have updated our ice-handling guidelines and are in the process of introducing new ice equipment storage across our estate.”
A spokesman for Caffè Nero described the findings as concerning and added: “A thorough investigation is now under way and the appropriate action will be taken.”
“99 per cent of our stores are rated as very good, good or satisfactory by their local environmental health officer – making us one of the most highly rated businesses on the high street,” he said.
None of the locations ‘contaminated’ have been revealed in the report.
Of the three Swindon Starbucks, all of them have a Food Standards Agency rating of 5, although none of the branches have been checked in the last year and Brunel Plaza not being checked since 2011!
Of the twelve Costa Coffee listed just two are listed as a four rating, the store at The Orbital (not the one in Next) and the one situated within Next at Mannington. The other ten are fives although Havelock Square and Signal Point (train station) were both checked last back in 2010!
The single Café Nero outlet on Bridge Street, checked this April is also listed as a five rating.
The first episode of the new Watchdog programme will air on BBC One tonight at 8pm.