The official in charge of the Spanish port of Vigo, Enrique López Veiga, has said the nearby northern Portuguese port of Leixões may attract up to 60,000 tonnes of frozen fish from China each year because new rules in Spain make it harder for his own port to handle the shipments, Jornal Económico reports.

The Portuguese newspaper quotes Mr López Veiga as saying Vigo may lose almost 10 percent its throughput of frozen fish.

The regulator also stressed that China is the third most important country of origin for goods handled at the northwestern Spanish harbour.

The report says the new rules in Spain mean extra paperwork for imports of frozen fish from China, requiring operators to provide a copy of the catch certificate.

The Portuguese rules require less paperwork, making an approval from Chinese authorities enough, Jornal Económico quotes the president of Vigo Harbour Authority as saying.