The Colombian government gave asylum to a Peruvian citizen, Haya de la Torre, in its embassy. It claimed it had a right to do this both under agreements between the states and in a local custom in the Latin American states.
- Can the Colombian government offer asylum under local custom?
No such local custom exists sufficient to be binding at international law.
The Court held that the party which relies on a custom of this kind has the burden of establishing that the custom exists in such a way that it has become binding on the other party, through constant and uniform usage of the states.
On the facts, very few states had ratified the conventions which Colombia relied on and there was significant discrepancy in the practice of asylum. Because of this, the Court was unable to find a custom which met the standard in the North Sea Continental Shelf case.
A party which claims a custom exists must prove that the custom was established in such a manner that it has become binding on the other party.