Who put the dishwashing liquid into the Waikato River at the weekend? That's what the Waikato Regional Council is trying to find out today.
Council staff are responding to reports of a foamy substance being discharged from Hamilton’s stormwater system into the Waikato River near Te Rapa.
The regional council is advising people who take water from the river immediately downstream from the site to exercise caution until the substance is identified.
The council was first contacted in the morning on Sunday by concerned members of the public who spotted the discharge from a pipe at the northern end of the golf course in the suburb of St Andrews.
While the discharge appears to be detergent-based, there are a number of samples which have been collected by staff for analysis.
In the meantime, the council is working with Hamilton City Council staff to identify the source of the discharge. The stormwater pipe has so far been traced to the Te Rapa industrial area.
Any members of the public with information which might help investigators is urged to contact Waikato Regional Council on 0800 800 401.