More dead fish emerged along the Sabeto River this week, sparking calls for an inquiry into the discovery.
This is the third such incident of dead marine life in water systems around Sabeto.
Permanent secretary for Environment Dr Sivendra Michael confirmed the discovery was made on Monday.
He said officers were sent to the site to collect samples for testing at Koronivia Research Station in Nausori and that the samples were with others sent to the laboratory earlier this month.
“Koronivia has confirmed that the analysis will be completed next week,” he said. “We will revert with results and our actions as soon as they are issued.”
Dr Michael said only two labs in Fiji could test the required parameters, which extend turnaround times.
“This is precisely why we are progressing work to establish an in-house MECC laboratory. Also, you would have noted the reported incident yesterday in the same locality as before.
“Our officers collected samples from four sites (upstream and downstream control points and impacted locations).
“These have been submitted to the labs.”