Sartaj Aziz said Kulbhushan Jadhav had been given a fair trial in Pakistan.
Pakistan today said the death sentence to Kulbhushan Jadhav was based on "credible" and "specific" evidence that prove his involvement in "spying and terror activities" and asserted that more active diplomacy is needed to arrest the "growing crises" in the Indo-Pak ties.
Rejecting Indian allegations that said otherwise, Pakistan Prime Minister's Advisor on Foreign Affairs Sartaj Aziz said that due process of law was followed in the trial of 46-year-old Mr Jadhav.
Mr Aziz in a detailed statement read out to the media at the Foreign Office said that India through its reaction was aggravating the situation.
"Kulbhushan Jhadav, who is responsible for espionage, sabotage and terrorism in Pakistan, has been tried according to the law of the land, in a fully transparent manner while preserving his rights, as per the Constitution of Pakistan," he said.
"His sentence is based on credible, specific evidence proving his involvement in espionage and terrorist activities in Pakistan," he added.
Mr Aziz "condemned" the Indian reaction over Mr Jadhav's sentencing and warned that it would further "aggravate the people-to-people hostility".
"I would like to ask India why Kulbhushan Jhadav was using a fake identity impersonating as a Muslim? Why would an innocent man possess two passports, one with a Hindu name and another with a Muslim name? Since India has no credible explanation about why their serving Naval Commander was in Balochistan, it has unleashed a flimsy propaganda campaign," he said.
"Inflammatory statements and rhetoric about 'pre- meditated murder' and 'unrest in Balochistan', will only result in escalation, serving no useful purpose," Mr Aziz warned.
"We condemn the baseless allegations from India, especially in the light of the fact that it was non-cooperation and lack of Indian response to Pakistan's request for legal assistance, due to which consular access has not been provided to Mr Jhadav," he said.
Mr Aziz said Mr Jadhav can appeal against the verdict of the military tribunal within 40 days to a military Appellate Court. He can file an appeal to the army chief within 60 days against the decision of the Appellate Court.
Mr Jadhav can file mercy petition to the President of Pakistan within 90 days if the army chief rejects the appeal for clemency.
Mr Aziz listed a several cases of terrorism in which he said Mr Jadhav was involved.
"He was part of sabotage and terrorism in which civilians and security personnel were killed," he claimed.
Mr Aziz also alleged that Mr Jadhav orchestrated attacks against minority Shia Hazara community in Quetta. He also said that India has not allowed consular access to many Pakistani prisoners for many years despite repeated requests.
Speaking in Kolkata, Home Minister Rajnath Singh however refuted Pakistan's claim of a fair trial being given to Mr Jadhav and said all efforts were being made to secure justice for him.
"I do not agree with what Pakistan has said. Kulbhushan Jadhav did not get a fair trial," he told a news conference.
"All efforts are being made to secure justice for Jadhav. We will do everything," he added.
(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)