Over three-and-a-half months have already passed but the murder of Ateef Sheikh, an Indian student of University of Science and Technology Chittagong (USTC), still remains a mystery.

A fourth-year MBBS student Ateef, 25, son of Abdul Khalique of Assam, was stabbed to death in his flat in the port city on July 15 allegedly by a fellow student of his country. The prime suspect, Maisnam Winson Singh, who allegedly tried to kill himself by hanging, was rescued from the same room.

Police could not unearth the murder motive although two arrestees, Winson and another roommate Gangmei Niraj, were remanded.

About the murder mystery, the investigation officer (IO) of the case, Inspector Santosh Kumar Chakma of Police Bureau of Investigation (PBI), said as the accused were foreigners, they were interrogated very carefully so that none could raise any question about the interrogation or investigation in the case.

Niraj, 25, was held after Ateef's father filed a case against six Indian and two Bangladeshi students of USTC on July 18.

PBI was entrusted to investigate the case on July 23. Police arrested Winson after he was released from hospital on July 23.

During interrogation, Winson said he could remember everything about the day, except how Ateef was murdered and how he was hanged, said Santosh.

Meanwhile, Niraj, during the interrogation, said on that night Ateef's girlfriend, who also lived in the flat, and he went to their respective rooms while the other five left the flat, and he did not know what happened inside the room of Ateef and Winson.

The IO said, “I have talked with all the eight people who attended the party that evening, their other classmates and also checked the CCTV footage of the apartment. From the statements and circumstantial evidences, we are almost sure that no outsider went to the flat at the time of the murder.”

“I am not sure whether Winson has really forgotten the incident or he is pretending,” he said.

“Upon court order, a six-member medical board was formed on August 10 and we are waiting for the report of the medical board,” he said.

Medical Board chief Prof Ashoke Kumar Dutta, head of medicine of Chittagong Medical College Hospital (CMCH), could not be contacted despite repeated attempts.

CMCH Director Brig Gen Jalal Uddin said the medical board will submit their final report after getting some test reports which will have to be performed outside CMCH.

About the knife and cleaver recovered from the crime scene, Zulfiqar Ali Haider, superintendent of police (PBI), Chittagong division, said Ateef's roommates used the cleaver to cut the belt for rescuing Winson and so police did not sent the weapon for forensic test as the report could be misleading.

Zulfiqar claimed police were very close to unearth the clue.