The family of Sarabjit Singh, who is on death row and lodged in a Pakistani jail since 1991, will move the International Court of Justice for his release.
"We will move the International Court for his release. Lawyer Suraj Singh will represent us," Sarabjit's sister Daljeet Kaur told PTI.
Sarabjit was convicted in Pakistan in the case of 1990 serial bomb blasts in Lahore and Multan that killed 14 people.
His family claims that he was a victim of mistaken identity and strayed into Pakistan from his village located on the border.
Though he was to be hanged on April one last year, the execution was put off indefinitely following Pakistani Prime Minister Yousuf Raza Gilani's intervention.
Pakistani lawyer Awais Sheikh, who took up Sarabjit's case in June last year, has filed mercy petition and also written a letter signed by thousands of Indians to Pakistani President Asif Ali Zardari pleading for the release of his client or at least commuting it to life imprisonment.