A teenage girl whose body was recovered from a sack with her hands tied in the Padma River in Sadar upazila of Pabna on Wednesday was allegedly raped and murdered by her cousin, police said after cracking the case within hours.

The body of Riya Akter, 15, a ninth-grade student and daughter of Azizul Pramanik of the Raghabpur area in Bharara union of the upazila, was recovered from the Padma River at Balrampur-Pirpur on Wednesday morning after locals spotted a sack.

Following the recovery of the body, multiple police units launched a coordinated investigation, using local CCTV footage and information technology.

Within hours, police cracked the case and arrested three suspects, including the prime accused.

At a press conference held on Wednesday evening at the office of the Pabna Superintendent of Police, Additional SP Md Rezinur Rahman disclosed the chilling details of the crime.

According to the police, Riya, a student at Moulana Kasim Uddin Smritee High School – was involved in a relationship with her cousin Naim.

"On Tuesday night, an altercation broke out between Riya and Naim at the latter's residence. At one stage of the argument, Naim raped the girl and subsequently strangulated her to death," Rezinur Rahman stated.

Following the murder, Naim, along with his accomplices, packed Riya's body into a sack and transported it via a private car to dump it into the Padma River.

Locals had previously reported seeing a suspicious, unidentified private car carrying four young men in the area around 10:30pm on Tuesday.

The vehicle had reportedly broken down while trying to leave the scene, forcing the occupants to seek help from local residents to push it to the Balrampur embankment.