His family members have urged people of the country to pray for his quick recovery
Senior journalist Mahfuz Ullah's health condition has deteriorated.
He is currently undergoing treatment at Bumrungrad International Hospital in Bangkok, Thailand.
The veteran journalist's brother, Mahbub Ullah, told Dhaka Tribune on Sunday: "Doctors at the hospital have informed us that his condition is very critical now. I urge everyone to pray for his quick recovery."
Mahfuz has been suffering from various ailments. He was flown to Thailand on April 10 for advanced treatment.
He has been politically active from his student days and had taken part in the 11-point movement. He was expelled from Dhaka College for his activism.
Born in Noakhali in 1950, Mahfuz Ullah obtained MA in physics and journalism from Dhaka University. He got involved in journalism when he was a student and had been associated with popular weekly "Bichitra" since its inception in 1972.
He also worked at the Bangladesh Deputy High Commission in Kolkata as a China expert and taught at DU's journalism department. Mahfuz hosted radio and television shows, and has been involved with leading Bangla and English dailies in Bangladesh.