Case 1 Massive pollution feared as oil spill tanker Prestige sinks off spain The shipwreck has led to a row over who is responsible, with Spanish officials saying the tanker had crossed into Portugals maritime salvage zone and lisbon vehemently denying the claim. The Prestige was being towed out to sea because Spanish, French and Portuguese authorities had all refused to allow it to dock at their ports. The tug was thought to have been heading toward an African portCase 1 Massive pollution feared as oil spill tanker Prestige sinks off Spain • The shipwreck has led to a row over who is responsible, with Spanish officials saying the tanker had crossed into Portugal's maritime salvage zone and Lisbon vehemently denying the claim. The Prestige was being towed out to sea because Spanish, French and Portuguese authorities had all refused to allow it to dock at their ports. The tug was thought to have been heading toward an African port