Wellington's Island Bay beach has reopened, a day after scientists detected sewage in a high bacterial count in the water.
Routine monitoring had found high amounts of the bacteria enterococci, which indicates microbiological pollution.
But the Wellington City Council says that further sampling on Thursday has established a lower levels of bacteria, and public health officials have cleared the beach to reopen.
Illnesses linked to contaminated water include diarrhoea, stomach cramps and vomiting.
