But initial testing of 12 water samples from tanks on three properties in the area has failed to find any trace of pesticides, including endosulfan and carbendazim.

Queensland's chief biosecurity officer and task force member, Ron Glanville, says further sampling will be conducted, but it is too early to draw any conclusions from the ongoing investigation.

"We're still investigating the fish kill that happened back in December and the results or the final results on that investigation won't be available probably until sometime in March," he said.

"There's some other sampling that's also going on in relation to the fish hatchery and the EPA are doing environmental studies as well."