Sylhet Chief Metropolitan Magistrate Court Judge Ziadur Rahman passed the order after Inspector Mohidul Islam of Police Bureau of Investigation (PBI), also the investigation officer of a case filed over Raihan's death, produced him before the court seeking a five-day remand.
A team of PBI arrested him on October 20 from Sylhet Police Lines. Later, he was produced before the court which gave investigators five days to interrogate him.
Meanwhile, another constable Harun was placed on five-day remand on Saturday.
On October 11, Raahan, a resident of Akharia in Sylhet city, was beaten to death in police custody, according to his family.
His wife Tahmina Akter Tanni filed a case at Kotwali Police Station the following day accusing a number of unidentified people.
Later, the case was transferred to PBI.