Tunda, who was nabbed by the special cell of the Delhi Police, from the Indo-Nepal border on August 16, was discharged from the hospital on Tuesday after he complained of a chest pain. HE was admitted to AIIMS on Friday.
Tunda's name was on number 15 in a dossier of "most wanted terrorists" that India handed over to Pakistan after 26/11 Mumbai terror attacks.
He had on Saturday, undergone a surgery to implant a pacemaker at AIIMS. According to hospital sources, his angiography and ECG reports were not normal.
He was earlier taken to the Safdarjung Hospital but was later shifted to AIiMS keeping in view the specialised care and security reasons.
The police had told the court that Tunda was a declared proclaimed offender in a case of recovery of explosive substances lodged in 1994 at south Delhi's Malviya Nagar police station under the provisions of stringent anti-terror law TADA.