Abdul Karim Tunda, the alleged Lashkar-e-Taiba operative and expert bomb-maker, was admitted to the hospital after he complained of chest pain. He was discharged after a few hours.
"Tunda complained of pain in his chest and stomach. He was taken to Safdarjung Hospital and put on observation. He was later discharged," a police officer said.
Doctors said Tunda was stressed as he is diabetic, the officer added.
Tunda, who is accused in more than 40 serial bombings in India, has been lodged in the Delhi Police's Special Cell office. He was arrested Aug 16 from the India-Nepal border.