Babul developed an extramarital affair with the NGO official when he was posted as additional superintendent of police of Cox’s Bazar in 2013.

Officer-in-charge of Panchlaish police station Abdul Kashem Bhuiyan said, “Police Bureau of Investigation (PBI) sent a letter for the investigation of the case. We are handing over the case to PBI.”

Earlier on the day, PBI submitted a final report in the case filed by Babul Akhtar over the murder.

Chattogram metropolitan police’s assistant commissioner (prosecution) Kazi Shahabuddin Ahmed told Prothom Alo that the report was submitted to the Chattogram court on Wednesday afternoon

Investigation officer of the case and inspector of PBI Chattogram, Santosh Kumar Chakma, said the final report has been submitted as the Babul’s involvement was found in the murder.

Police sources said police submit final report of a case and file a fresh case if plaintiff of a case himself is found involved with the murder.

Mitu was hacked and shot dead in broad daylight near her house in Chattogram on 5 June 2016.

Babul filed a case over the incident saying his wife might become a target for his anti-militant activities.

But the course of the case took a twist within two weeks. Mitu’s parents repeatedly accused Babul of the murder. Babul was sacked from the police but the investigation was stalled.

Read more from Crime and Law