68-year-old convict of the 1993 Mumbai serial blasts case, Jalees Ansari, went missing on Thursday morning while being on parole, officials said.
Jalees Ansari, a resident of Mominpura in south Mumbai's Agripada who is serving a life term, is suspected to be involved in many bomb blast cases across the country, an official said.
He was on parole for 21 days from the Ajmer Central Prison, Rajasthan, and was expected to surrender before prison authorities on Friday, he said.
During the parole period, he was ordered to visit the Agripada Police Station everyday between 10.30 am and 12 pm to mark his attendance, he said.
However, Jalees Ansari did not visit the police station on Thursday during the designated time, the official said.
In the afternoon, his 35-year-old son Jaid Ansari approached the police station with a complaint about his "missing" father, he said.
According to the complaint, Jalees Ansari woke up in the early hours and told family members he is going to offer namaz, but did not return home.
On the son's complaint, the Agripada Police registered a missing person's case, the official said.
The Crime Branch of the Mumbai Police and the Maharashtra ATS have launched a massive manhunt to trace him, he said.
Jalees Ansari, who is known as Doctor Bomb, was allegedly connected with terror outfits like SIMI and Indian Mujahideen and taught terror groups how to make bombs, he said.
He was also questioned by the NIA in 2011 in connection with the 2008 bomb blast in Mumbai, he said.