Police recovered the throat-slit body of an adolescent girl from inside a cabin of a Patuakhali-bound launch in the capital's Sadarghat this afternoon.

The deceased was identified as Parul Aktar, 16, a class-9 student of Keraniganj.

The vessel workers caught and handed over Al Mamun, a third year accounting student of Kobi Nazrul College, to police, said Inspector (investigation) Parvez Aktar of Kotwali Police Station.

A cabin boy saw blood coming out from a cabin of the launch around 4:30pm, police said quoting staff.

He informed other staff and they found Mamun inside the cabin. They caught him and informed police. Later, police recovered the body and a knife used for the murder from that cabin.

Mamun, who used to teach the girl at her home for two years, claimed of having an affair with her.