Ailing virologist Khalil Chishti, detained in Rajasthan for nearly two decades on a charge of involvement in a murder, arrived in Pakistan on Tuesday after being given special permission by India's Supreme Court to return home to meet his family.
The 82-year-old Chishti flew from New Delhi to Islamabad in a special aircraft sent by President Asif Ali Zardari.
He was received at the Benazir Bhutto International Airport by interior minister Rehman Malik, who presented him a floral wreath.
A large crowd, including workers of the Pakistan People's Party, showered petals on Chishti as he emerged from the airport in a wheelchair.
"I had no hope at all but it is thanks to Allah that He gave an opportunity to President Zardari to travel to India and to take up my issue (with Prime Minister Manmohan Singh)," Chishti told the media at the airport.
"The Indian Prime Minister is a merciful person and heard the plea of Pakistani leaders. He helped me after seeing my condition," he added.
Malik thanked President Zardari and Prime Minister Singh for facilitating the release of Chishti.
He said that during a meeting with Singh in Delhi on April 8, Zardari took up Chishti's issue before other bilateral matters.
The President also took follow-up action and sent his special aircraft to bring back Chishti, Malik said.
Footage aired on TV news channels showed Chishti's home in the southern port city of Karachi had been decorated by his family. His wife and daughters stood on a balcony and waved to a large gathering that had gathered outside the house.