A state may not enforce a foreign-country judgment in the following cases:............
;
- The judgment is repugnant to the public policy of the state where enforcement is sought;
- In the case of jurisdiction based only on personal service, the foreign court was an inconvenient forum for the trial; or
- If the judgement is not conclusive
The following issues are considered:
- Whether the defendant was properly served with notice of the proceedings and given a reasonable opportunity to be heard which raises general principles of natural justice and will frequently be judged by international standards (hence, the rules for service on a non-resident defendant outside the jurisdiction must match general standards and the fact that the first instance court's rules were followed will be irrelevant if the international view is that the local system is unjust);
- Whether the judgment offends the public policy of the local state.
https://en.wikipedia.org/wiki/Enforcement_of_foreign_judgments
Some grounds he may use in his defence ?