A Blenheim pool complex has been closed because of a possible link to people falling ill with a serious gastroenteritis bug.
Marlborough District Council said the Stadium 2000 trust was advised by public health officials about reports of cases of cryptosporidium.
Medical Officer of Health Andrew Lindsay said seven of the 10 reported cases involved people who had visited the complex.
He said other parts of the country were also reporting a higher than usual number of cases, and the public health service was also looking for other possible sources of contamination.
Cryptosporidium causes diarrhoea, stomach cramps and sometimes vomiting.