The Cook Islands government has dismissed complaints about the alleged pollution of a stream by the company installing Te Mato Vai, the new water reticulation system on Rarotonga.
Takuvaine landowners have suggested the company released chlorine into the stream that runs through the property, despite assurances that this would not happen.
One landowner, Tere Carr, said they had been told that disinfected water, used to flush the sedimentation tank, would be held for up to six weeks to allow the chlorine to evaporate.
But she said that appeared not to have been the case.
"What we suspect happened last Monday is that the chlorinated water from one of the tanks was released into the stream that runs past where the works are located. So there's real concern from the landowners on the Takuvaine Intake that this could have happened.
"As a result there was evidence of some of the animals in the stream having been affected and having died."
However, Secretary of Finance Garth Henderson, speaking for the government, said the complainants were wrong.
There was no evidence to back such claims, he said, with no photos of the supposedly dead fish and eels the landowners say had died.
The government remained confident in the work being done by the company and he was happy this issue had been included in a series of complaints from Takuvaine landowners to be ruled on by the courts next year.
The Cooks government has been at loggerheads with several groups and environmentalists over its enthusiasm for using chlorine to disinfect the water, with opponents saying no sterilisation is necessary.