Former Chief Justice ABM Khairul Haque was rushed to Bangabandhu Sheikh Mujib Medical University Hospital on Monday after suffering a heart attack in prison.
Prison officials confirmed that he was immediately shifted to the hospital and placed under medical supervision.
His son, Ashiqul Haque, said doctors are closely monitoring his condition.
Detectives had earlier detained Khairul Haque from his Dhanmondi residence in the capital on July 24.
He was later shown arrested in connection with a murder case filed with Jatrabari Police Station, and a Dhaka court granted police remand for his interrogation.
Khairul Haque has for years remained a divisive figure in Bangladesh’s legal and political landscape.
He has faced sharp criticism for verdicts viewed as politically motivated, as well as for spearheading constitutional amendments that many believe were designed to serve partisan ends.