"He was never involved in any terror activities, the authorities can continue to say what they want," Qureshi's father said.
The Delhi Police on Monday arrested Qureshi, the co-founder of Indian Mujahideen (IM) and ideologue of Students Islamic Movement of India (SIMI).
Qureshi, one of the 'most wanted' fugitives of the National Investigation Agency (NIA), carried a reward of Rs. 4 lakh on his head.
He is the alleged mastermind of 2008 Ahmedabad serial blasts, which claimed 56 lives.
Interpol had issued a red notice against him for his role as the main conspirator in the serial blasts. He is also a suspect in the 2006 Mumbai train blasts. (ANI)