1. If a non-contractual obligation arising out of unjust enrichment, including payment of amounts wrongly received, concerns a relationship existing between the parties, such as one arising out of a contract or a tort/delict, that is closely connected with that unjust enrichment, it shall be governed by the law that governs that relationship.

2. Where the law applicable cannot be determined on the basis of paragraph 1 and the parties have their habitual residence in the same country when the event giving rise to unjust enrichment occurs, the law of that country shall apply.

3. Where the law applicable cannot be determined on the basis of paragraphs 1 or 2, it shall be the law of the country in which the unjust enrichment took place.

4. Where it is clear from all the circumstances of the case that the non-contractual obligation arising out of unjust enrichment is manifestly more closely connected with a country other than that indicated in paragraphs 1, 2 and 3, the law of that other country shall apply.