Investigators have found several inconsistencies in the statements of Ahmed Shahriar Reza Dwip, a friend of former Bangladesh Air Force Flight Lieutenant KM Tahsif Souri, whose death has raised fresh questions.
Dwip has provided different accounts of what happened on the day of the incident, why he returned home alone and how Tahsif went missing. Investigators are also examining whether he initially withheld any information.
In his latest account, Dwip claimed that several people wearing police uniforms chased them on the day of the incident. Tahsif fell into the water while fleeing from them.
However, the Police Bureau of Investigation (PBI) has yet to establish whether those chasing them were actual police personnel, drug dealers or someone else.
Enayet Hossain Mannan, additional deputy inspector general of PBI's Dhaka Metro North, today (30 October) said all the information provided by Dwip was being verified.
"He [Dwip] says that some people wearing police uniforms chased them. We are investigating who chased them. Whether they were drug users will be known after the autopsy. He has said many things, but everything is being verified," he said.
The investigation agency is also examining whether any drug-related incident took place at the location, which is known as a spot for drug transactions.
The PBI said whether Tahsif and Dwip were under the influence of drugs would be determined after receiving the autopsy and dope test reports.
Dwip was taken to PBI's Dhaka Metro North office last night (29 October) for questioning. This morning, the investigation team visited the Mazar Basti area under Tongi West Police Station with him.
Based on information provided by Dwip, the team recovered a motorcycle from the area. However, investigators have yet to conclusively establish whether it belonged to Tahsif.
Inconsistencies in Dwip's statements
PBI Inspector Syed Sajedur Rahman said the PBI was conducting a shadow investigation alongside the River Police into Tahsif's death.
He said that as part of the investigation, Dwip was brought in for questioning, during which he provided various pieces of information. Based on his statements, investigators recovered the motorcycle which likely belonged to Tahsif.
According to Dwip, the two had travelled from Uttara to the Mazar Basti area of Tongi on separate motorcycles. At one point after reaching the area, they became separated. Dwip said he searched for Tahsif for nearly an hour but, failing to find him, returned home alone on his motorcycle.
However, several questions remain unanswered: how the two became separated after travelling there together, why Dwip returned alone without finding Tahsif, and why he did not mention the alleged chase earlier.
Sajedur said there were inconsistencies and unclear aspects in Dwip's statements. "He is giving different accounts at different times. We are trying to establish why they came to the area, what they did there, and what happened afterwards.
"Based on Dwip's statement, we have so far established that they went there. The remaining information is being verified."
CCTV footage shows them leaving together
CCTV camera footage from the garage beneath Tahsif's residence shows Dwip arriving on a motorcycle around 6:24pm on 27 October, the day Tahsif went missing.
A short while later, Tahsif came down from his home upstairs. The footage shows him struggling slightly to start his motorcycle, pushing it to get the engine running. The two were subsequently seen leaving the residence on separate motorcycles.
According to Dwip, they had gone to a garage that day to have Tahsif's motorcycle repaired. Law enforcement agencies have also spoken to people at that garage.
Dwip said they later had dinner at a restaurant in Uttara and parted ways in the Uttara House Building area at around midnight.
Dwip claimed he searched for Tahsif for nearly an hour after they separated before returning home alone. PBI said location data showed that Dwip reached home sometime between 2am and 2:30am.
Motorcycle recovered
Since Tahsif's body was recovered on Wednesday afternoon (28 October), law enforcement agencies had been searching for the motorcycle he used.
Based on information and identification provided by Dwip, PBI recovered a motorcycle from the Mazar Basti area under Tongi West Police Station this morning.
Senior PBI official Enayet said investigators suspected that the motorcycle belonged to Tahsif. "However, its actual ownership will be confirmed after checking the registration, engine, and chassis numbers."
According to him, the location where the motorcycle was recovered is approximately 3 to 3.5 kilometres from the spot near Rajabari Ghat in the Turag River under Uttarkhan Police Station, where Tahsif's body was recovered.