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.
Teenager killed and child left in critical condition after Belfast road crash
By Claudia Savage (Press Association)
Stormont leaders and chief constable in show of unity against station attack
By Rebecca Black and Claudia Savage (Press Association)
Car driver and motorcyclist killed in Lisburn collision
By Claudia Savage (Press Association)
Firefighters continue to battle ‘soul‑destroying’ wildfires in Mourne Mountains
By Claudia Savage (Press Association)
Political leaders unite to condemn ‘cowardly’ attack on PSNI station
By Claudia Savage (Press Association)
Download the Q Radio app to keep listening, wherever you are! It's available on Apple and Android devices.
Download from the App Store Download from Google Play
