India has argued in the International Court of Justice that Pakistan violated international laws by not allowing it access to Kulbhushan Sudhir Jadhav.
Mr Jadhav was arrested in Balochistan in March 2016 and convicted last month.
India denies Mr Jadhav is a spy, and Pakistan denies kidnapping him.
Sitting in The Hague, the court rejected Pakistan's argument that it did not have jurisdiction over the case, and said it would hear the case and seek arguments from both sides.
