BRUSSELS (Reuters) – The European Commission has questioned Greece over its port procedures after it emerged that a tanker which is threatening Spain with a major oil slick recently called at a Greek harbor, it said yesterday. [The Greek government countered that the ship had stopped in Greece on June 7 in transit and therefore port authorities had no obligation to inspect it. It added that the Bahamas-flagged ship was operated by a company registered in Liberia.] Spanish authorities are battling to prevent the Bahamas-flagged 26-year-old tanker, which was damaged in storms off the Galician coast on Wednesday, from spilling its load of more than 70,000 tons of fuel oil. EU law requires ports in the 15-country bloc inspect 25 percent of ships that call. The rules will be tightened from next July, when the inspections must be targeted at older ships like the single-hull Prestige. Under political pressure from the EU following the Erika tanker spill off northeastern France in 1999, single-hull tankers will be phased out worldwide in favor of sturdier double-hull vessels. None will be allowed in EU ports after 2015. «It appears that the tanker Prestige called at the port of Kalamata for bunkering in June 2002,» said an official at the Commission, the EU’s executive arm. The vessel has not been inspected since 1999, he added. The incident sparked a minor diplomatic row between Spain and Britain, with Madrid claiming the vessel was headed for the British colony of Gibraltar on Spain’s southern tip and that despite regular calls there had not been inspected. The Commission has already asked Britain for details of its policies on inspecting ships calling at its ports. It has now sent the same request to Greece, a spokesman said. The Commission can take court action against member states that it believes have broken EU law.