Elahi had decided that if he gets to meet Zardari he would request the Pakistani president to release all the Indian prisoners of war in Pakistani jails.
Elahi had served two decades in several Pakistani prisons from 1977-1996 on the charge of spying for India. He was Zardari's prison mate along with several leaders of Pakistan People's Party (PPP) in the Karachi Central Jail in 1986-87.
"I had been serving in the same prison along with Zardari and Benazir Bhutto during the military rule in Pakistan under Zia-ul-Haq. We used to meet Zardari on Sundays in the courtyard of the jail," Elahi said in an exclusive interview.
Elahi, a seasoned spy of the late 60s and 70s, had twice crossed over to Pakistan - once via East Pakistan (now Bangladesh) and once via the western border. He recollected how he had developed a good rapport with Zardari in prison.
"He (Zardari) used to talk about the political situation in Pakistan, and the misrule and suppression of Zia. He had a strong following inside the jail," he recalled.
According to Elahi, Zardari was "sympathetic" to the plight of Indian prisoners.
"Zardari was quite influential and he was sympathetic to Indian POWs. The Indian POWs used to wash the clothes of Pakistani prisoners and do menial chores for them. They would also do it for Zardari, but Zardari was sympathetic to them. He would speak to them, buy them soap and sweets," said Elahi.
Initially, Elahi spent nearly 10 years in Pakistan from 1968 to 1977 after spying in various government organisations, including the Pakistani army and police.
The 52-year-old spy, who still bears the scars of Pakistani torture all over his body, said during his stay in Pakistani jails he came across hundreds of Indian POWs and fishermen who are suffering in Pakistan for years.
"I have met hundreds of Indian prisoners there, most of them POWs. Many of them have either gone mad or have lost their memory due to inhuman torture. They can't even recollect their names."
He regretted that neither the Indian government nor the Indian Army has done enough to bring the "real heroes" back home.
Elahi had written to the Pakistani High Commission in India seeking an appointment with Zardari during his six-hour visit to India, but did not receive a reply.
"I didn't get a reply from Pakistan high commission. But the sad thing is that I had also written to the Indian president ( Pratibha Patil), but she too didn't reply. I am disheartened by this indifference of both the countries towards the POWs."
Since his release in 1996, Elahi has been a voracious campaigner for release of Indian POWs and prisoners. During the BJP-led NDA rule he sat on a demonstration in New Delhi and even threatened to commit suicide in front of parliament. The then defence and foreign minister Jaswant Singh had assured him that the Indian government was consistently taking up the issue with Pakistan.
"The Indian prisoners are tortured everyday, I was also tortured. In 1996 there were around 1,335 prisoners. Now the figure may have increased or decreased, but still there are several Indian POWs in Pakistan," he said.
Elahi recollected how officers close to Zia tried to lure him with money and promise of release in exchange for killing former Pakistan prime minister Zulfiqar Ali Bhutto, who was then languishing in Lahore jail after a coup by the country's army.
"I was offered a blank cheque and a promise of release provided I assassinate Zulfiqar Ali Bhutto. But I refused to carry out the act."
Elahi is upset that in India "most Muslims are viewed with suspicion".
"Muslims are patriots. They should not been seen with an eye of suspicion. Muslims are ready to die for their motherland," said Elahi.
Zardari will have lunch with Indian Prime Minister Manmohan Singh, followed by a one-on-one meeting, after which he will visit the Sufi shrine of Khwaja Moinuddin Chisti in Ajmer and fly back in the evening.