Moudud was shifted to Intensive Care Unit (ICU) of Mount Elizabeth Hospital on Tuesday afternoon following the deterioration of his physical condition, said his personal assistant Mominur Rahman Sujon.
He said Moudud has been struggling for a few days to get oxygen due to lung congestion.
Also read: Moudud taken to Singapore for treatment
Besides, Sujon said Moudud has serious kidney complications.
On February 1, the BNP leader was admitted to Mount Elizabeth Hospital in Singapore for advanced treatment. His wife Hasna Moudud, daughter of famous poet Jasimuddin, is there with him.
Also read: BNP leader Moudud undergoes pacemaker implant surgery
On December 30 last year, Moudud, in his 80s, was admitted to Evercare Hospital in Dhaka as he had fallen ill due to low level of haemoglobin. He also suffered a mild stroke while undergoing treatment at the hospital.
On January 7, a permanent pacemaker was implanted in the heart of the ailing BNP leader.
Also read: BNP leader Moudud hospitalised
Moudud Ahmed is one of the founding members of the BNP. He joined Jatiya Party in 1985 and served as prime minister and vice president in military ruler HM Ershad’s government.
After the fall of Ershad, Moudud returned to BNP in 1996 and he was made law minister in Khaleda Zia's government in 2001.