He has been at the BSMMU's prison cell since his arrest in Jan, 2012.
Dhaka Central Jail's Senior Supreintendent Farman Ali said that he was taken to the CCU around 8.30 am on Tuesday as his condition deteriorated.
His son Abdullahil Aman Azmi informed bdnews24.com that they have been told that his father was shifted to the CCU due to respiratory complications following rise in blood pressure.
The 92-year-old former Jamaat supremo has been found guilty by the war crimes tribunal for conspiracy, planning, incitement, complicity (abetment) and murder.
On July 15, 2013, the International Crimes Tribunal sentenced him to 90 years in jail on five charges.
The court said Azam will have to serve the sentence "consecutively or till his death".