Fishermen have kept the crocodile in a pond adjacent to the river.
Fisherman Anwarul, a resident of Nagshosh, Natore Sadar upzila, went to the river for fishing in the early hours of the day.
At one stage, he found a crocodile in his net. After frantic effort of locals, he recovered the crocodile and kept it in a pond near the river and informed the matter to the upazila administration.
UNO Nazrul Islam said he had already informed the matter to livestock department in Rajshahi.
After their arrival, necessary steps would be taken for the crocodile.