A man, who was detained by the Rapid Action Battalion on Friday as a suspect of RAB office attack at Ashkona, died in a hospital.
The victim was identified as Hanif Mridha, a resident of Amragachhia village of Amtali upazila in Barguna.
However, the family of the dead could not be reached for comments.
Airport police inspector Ezaz Shafi said RAB-1 members picked up Hanif from a bush beside Munmun Kabab shop near Hazrat Shahjalal International Airport at 4:15pm on Friday.
Hanif died at Kurmitola General Hospital 1:25 hours after his arrest, and an unnatural death case was filed in this connection with the police station at 1:35am early Saturday, the inspector said.
According to the death certificate, Hanif died of cardiac arrest, and the body was sent to Dhaka Medical College Hospital (DMCH) morgue on Saturday, Ezaz added.
DMCH sources said the Airport police members brought the body of Hanif Mridha around 5:00am while four vehicles of RAB also accompanied.
Earlier on Friday, a suicide bomber rattled the Ashkona RAB office, killing himself by detonating a bomb.
RAB's legal and media wing director Mufti Mahmud Khan said a young man was trying to enter the camp and when the RAB members challenged him, he detonated the bomb that was strapped to his body.
The blast killed him on the spot and injured two RAB members.