An unnatural death case was filed with the Jhalakathi Sadar police station over the launch fire incident on the Sugandha River in Jhalakathi early Friday.
Jhalakathi Sadar police officer-in-charge (OC) Md Khalilur Rahman told BSS that village police member Md Jahangir Alam filed the case last night.
At least 40 people were killed and over several injured as a launch carrying hundreds of passengers caught fire on Sugandha River at Gabkhan-Dhansiri area under Sadar upazila in Jhalakathi on early Friday.
The launch was travelling to Barguna from the capital.
Jhalakathi police station SI Md Nazrul Islam has been assigned to investigate the case, the OC added.