Kulbushan Jadhav was arrested in March 2016 "for his involvement in espionage and sabotage activities against Pakistan," and sentenced to death last month.
On May 8, India initiated proceedings at the Hague against its regional rival, accusing Islamabad of "egregious violations of the Vienna Convention on Consular Relations" in the sentencing of Jadhav, according to a statement released by the ICJ
India requested the ICJ order Pakistan not to execute Jadhav until the court can issue a judgment based on India's claims.
is the principle judicial arm of the United Nations and settles disputes between member states in accordance with international law.
India alleges Jadhav was "kidnapped" from Iran where he was on business after retiring from the Indian Navy. He was arrested by Pakistani authorities in Baluchistan on March 3 last year.
Indian authorities say they learned of his arrest through a press release nearly three weeks later and were refused consular access multiple times, in violation of the Vienna Convention.
A military court charged Jadhav on April 11
under the Pakistan Army Act 1952 and the Official Secrets Act 1923, both of which provide for the death penalty.
India described the sentencing as an act of "brazen defiance" of the Vienna Convention
and warned executing Jadhav would be an act of "premeditated murder."
In a statement, Amnesty International said
military courts, which were used in Jadhav's case, have been linked to coerced confessions and unfair trials.
As UN member states, India and Pakistan are both de facto members of the ICJ. Both are also signatories to the Vienna Convention's rules regarding settlement of disputes
Under the protocols, all disputes arising out of the interpretation or application of the Convention -- which governs diplomatic relations between states -- come under the "compulsory jurisdiction" of the ICJ.
According to the ICJ, any signatory state "undertakes to comply with any decision of the Court in a case to which it is a party." Decisions by the court are binding and noncompliance is very rare
In its petition to the court, India requested that Pakistan's sentencing of Jadhav be declared illegal and Islamabad directed to "release the convicted Indian national" in the event Pakistan does not annul its domestic judgment in the wake of the ICJ's ruling.
Sartaj Aziz, foreign affairs adviser to Pakistan's Prime Minister, said the government was "examining this issue."
On Twitter, Pakistan Defense Minister Khawaja Asif said India's letter to the ICJ was an "attempt to divert attention (from) state sponsored terrorism" in Pakistan.
Jadhav had been "convicted of offenses against (national) security," Asif said.
History of spying
Espionage has long been a fraught subject between Pakistan and India.
In 2013, Sarabjit Singh, an Indian man sentenced to death for spying, died after being attacked by fellow inmates in a Pakistan jail.
More than 40 alleged Pakistani spies have been arrested in India since 2013, according to the government.
India does impose the death penalty but has only carried out three executions since 2007, according to a recent report by Amnesty International on the global death penalty
Meanwhile, Pakistan, which executed 87 people last year, is the world's fifth biggest executioner.