A probe is continuing into the extent of the damage caused by a pollution incident on a tributary of the Moyola.
Dead fish were discovered on a two mile stretch of the Altagoan River, near Draperstown on Friday.
It’s understood the source of the problem has been traced to nearby premises.
A spokesperson for the Department of Agriculture, Environment and Rural Affairs says the investigation has been continuing over the weekend.
However bad weather has been hampering the probe.
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