The son of Bangladesh's last prime minister has been remanded in custody for a month while corruption charges against him are investigated.
Mr Rahman is charged with extorting money
Lawyers acting for Tarique Rahman, the eldest son of former Prime Minister Khaleda Zia, say that he was sent to Dhaka's Central Jail late on Monday.
The authorities say his arrest is part of a nationwide crackdown on graft.
Mr Rahman is charged with extorting $147,000 from a construction company, police say. He denies wrongdoing.
He was arrested on 7 March, and his bail application was rejected late on Monday.
On Tuesday officials say he was moved to a prison hospital after complaining of pains in his chest and head. They say his condition is now stable.
He appeared in court wearing a bullet-proof jacket for his own security late on Monday after four days of questioning.
Mr Rahman denied the allegations against him, and a second bail petition is due to be heard on 19 March.
His mother, Khaleda Zia, ended her five-year term as prime minister in October and handed over power to an interim authority.
It is led by former Central Bank chief Fakhruddin Ahmed, who has vowed to eliminate corruption from politics before announcing a date for overdue parliamentary elections.
Security forces have detained scores of people, including 15 former ministers, since a state of emergency was imposed in Bangladesh in January. Luxury cars have been seized and bank accounts frozen.
Correspondents say that Mr Rahman is the most prominent person so far to be arrested.
He was preparing to contest a constituency in his home district, Bogra, in the north of the country.