Fishes were found poisoned in the Panganodi river near Jalpaiguri town since the last four days.
Fisheries department Jalpaiguri incharge Partha Sarathi Das said today that cause for the fishes found floating was being investigated and samples sent for examination.
SDO Jalpaiguri Sima Halder said preventive measures have been taken so that the dead fishes consumed by the local people do not cause harm.
It is suspected that the pesticide used by the nearby tea gardens could have drained into the river causing the poisoning of the fishes.
