Law enforcement arrested war crimes suspect Syed Mohammad Kaiser from the American Centre area of Vatara following the arrest order issued by the International Crime Tribunal.
Vatara police station officer-in-charge Ziaul Haq confirmed the matter to banglanews.
He said: “He fell sick soon after police arrested him for his alleged involvement in war crimes in 1971.”
Later, he was taken to Apollo Hospital and is now undergoing treatment at the coronary care unit (CCU) under police custody.
Earlier on May 15, ICT 2 issued an arrest warrant against Kaiser, a leader of the local peace committee in Habiganj, in connection with crimes against humanity and genocide committed during the Liberation War.
The ICT investigation team is looking into allegations against him.
His force allegedly committed genocide, murder, rape, arson, looting and forceful conversion to Islam during the 1971 war.
Syed Kaiser lived in Madhabpur upazila in Habiganj district during the Liberation War.
He was a state minister for agriculture in 1989.