Fourteen-year-old Rakibul Hasan Emon’s body was recovered from a ditch at Kamartala area of Bandar Upazila.
The ninth grader was the son of Nura Miah, an expatriate in Dubai, hailing from Dhamgar Union.
Police said they arrested three persons in connection with the murder on Wednesday night.
They are Saidur Rahman, Shahjahan Ali Jibon and Emon’s cousin Al-Amin.
Bandar Police Station OC Akhter Morshed said they could locate the body after they confessed to the killing.
Emon was abducted on Jan 25 from his home. The kidnappers later demanded ransom from his mother and threatened to kill the boy if they were not paid the money, according to the police officer.
The mother filed a case against Emon’s uncle Piyar Hossain, brother-in-law Jasimuddin and cousins Shahar Banu, Noor Alam and ‘Masud’.