A three-year-old girl of the town was killed allegedly by her paternal uncle as the victim's mother rejected the latter's illicit proposal.
Additional Superintendent of Police Md Alamgir Hossain came up with the clue to the murder at a press conference in the town yesterday.
Halima, daughter of Amir Ali of Bhadughar area, was found murdered in the town on Saturday.
Helal Mia, 26, had been giving illicit proposal to Halima's mother for over a month. As the woman rejected, Helal along with his accomplice Rubel Mia, helper of a mason, planned to kill Halima.
On Saturday, Helal and Rubel lured the kid with potato chips and took her to a narrow lane in the area. Later, Helal strangled Halima.
The next day, police detained Helal and Rubel and during interrogation, they confessed to their involvement in the murder, said the police official.