Rab officials would start interrogating suspended police officers Pradeep Kumar Das, Liaqat Ali, and Nandadulal Rakhshit from today.
"The three accused placed on remand will be taken in our custody," Lt Col Ashik Billah, director of Rab's media wing, told The Daily Star yesterday.
The suspended police officers were each placed on a 7-day remand on August 6 in the case for shooting dead Major (retd) Sinha Md Rashed Khan in Teknaf.
Pradeep was an officer-in-charge, Liaqat an inspector, and Nandadulal a sub-inspector of police. Liaqat is the main accused in the case.
Four other accused, suspended sub-inspectors Litan Miah and Tutul, and constables Mostofa, Safanur Rahman, Kamal and Abdullah Al Mamun were sent to jail.
Meanwhile, the authorities have decided to transfer every staff member from Teknaf Police Station, a senior official of the force told The Daily Star yesterday. There were around 60 to 70 policemen there before Sinha was shot dead at a checkpost on July 31.
In another event on Saturday around 8:00pm, Border Guard Bangladesh (BGB) men at a check post on Marine Drive Road found Tk 1.90 lakh in cash in possession of two constables of Teknaf Police Station. They were travelling in a microbus.
The constables reportedly failed to explain the money.
The BGB men let them go after high officials of the forces talked to each other.
A high official of BGB 2 battalion confirmed the incident to The Daily Star.
According to sources, the two constables were known to be in the inner circle of OC Pradeep who used to travel with them.
Meanwhile, assistant sub-inspectors Mithun Bhowmick and Sanjib Datta -- also known to be close to the disgraced OC -- have been transferred from Teknaf to Cox's Bazar District Special Branch and Pekua Police Station, according to officials.
Police authorities suspended all the seven accused and appointed a new officer-in-charge for Teknaf Police Station.
Jamil ul Haque, Rab Assistant Superintendent of Police and also the IO of the case, yesterday quizzed the four accused at the Cox's Bazar District Jail gate for the second day.
Superintendent of the jail Mohammad Mokammel Haque said the IO started interrogating the accused from 10:00am yesterday which continued till 2:00pm.
Rab Director Ashik Billah also said they appealed to a Cox's Bazar court for the postmortem report of ex-major Sinha. The IO would attach the postmortem report with a case docket after receiving it from the people concerned.
He also said the IO of the case yesterday visited the spot and talked to locals about the incident. The IO will talk to the witnesses, review those and take necessary steps, he added.
Ex-Major Sinha, 36, had been making travel documentaries for a YouTube channel called Just Go. On July 31, he was returning to Cox's Bazar from Teknaf. His car was stopped at Shaplapur on Marine Drive.
The police claimed that they tried to search the vehicle, and Sinha aimed his pistol at them prompting them to shoot back in self-defence. They also claimed that they seized drugs from the vehicle.
However, witnesses gave different accounts of the incident. They said Sinha got down from his car, put his hands over his head, and then the police shot him.
Two cases have been initiated over the incident. But the police account raised many questions, prompting the government to form a committee to investigate the incident.