A disgusted gran claims she found human excrement by the poolside at Feltham Airparcs leisure centre.
Penny Robinson visited the sports facility in Uxbridge Road with her daughter and grandchildren but was appalled by what she found there.
"I was disgusted with the state of the building. There was human excrement around the pool area that had been trodden in," she said, adding it was eventually cleared up when it was pointed out to staff.
"The changing rooms were filthy. The group one had graffiti, women's panty-liners, hair and litter all over the floor," she added.
Mrs Robinson, 53, also claimed the swimming pool itself was dangerous and a changing table did not have straps to hold babies in place.
"The pool had metal support posts which were badly corroded, and areas held together with silver tape around the small pool with the slide," she said. "A lady cut her foot on the plastic grid over the filter in the small pool. She reported this but nothing was done and she was telling people to be careful.
"The shower area in the female changing rooms was full of rubbish, hair and bottles, and poolside toilets had a sink full of sandwiches."
Fusion, which runs Feltham Airparcs on behalf of Hounslow Council admitted there had been a 'regrettable drop in the cleaning standards at the pool' which was 'clearly its responsibility'.
"Unfortunately, accidents do happen and while no one else reported witnessing the excrement issue, it was duly dealt with according to health and safety guidelines," a spokeswoman said. "Fusion recognises how important cleanliness is to our customers and has recently appointed cleaning contractors to undertake initial deep cleans and overnight programmed cleaning."
"Although clearly there was a lapse on the occasion of Mrs Robinson's visit, we feel that the cleaning situation is now being managed through the extended cleaning roster, regular checks by staff and formal inspections."