Jundal's father Syed Zakiuddin had not been keeping well for some time and his condition deteriorated when he came to know about his son's arrest yesterday, neighbours said.
Zakiuddin, who is in his 60s and has suffered two heart attacks in the past, was admitted to Civil Hospital, from where he was discharged today, they said, adding he once worked as an insurance agent.
Jundal's mother suffers from diabetes. Police are keeping a strict vigil outside Jundal's house, located in Hatti Khana area of this city in Central Maharashtra.
One of their neighbours Mukram Pathan said, "Abu's parents are unwell. But they say if he is found guilty, they would not mind even if he is hanged in front of them."
According to sources close to the family, Jundal has three sisters, two of whom are married.
The family has another house in Georai tehsil of Beed district, but nobody is staying there for the last two months, they said.
Jundal was arrested by Delhi Police after he was deported from Saudi Arabia on India's request. He is believed to be one of the key handlers of terrorists involved in the November 2008 terror attacks on Mumbai.