A French submarine has discovered three more cracks in the stern section of the sunken oil tanker Prestige that could leak yet more fuel oil onto the ravaged Spanish coastline, Spain said on Monday. The Prestige, laden with 77'000 tonnes of thick, toxic fuel oil, snapped in two and sank off the prime fishing coast of Spain's northwestern Galicia region on November 19, leaving a foul black tide in its wake. The spill, which could prove to be Spain's worst ever environmental disaster, has thrown tens of thousands of fishermen out of work, devastated wildlife and tarred the Spanish government with criticism over its crisis management. The crew of the submarine Nautile, hired by Spain to probe the wreckage on the ocean floor 3.5 km (2.2 miles) beneath the surface, has found fuel oil leaking from the shattered hull of the separate bow and stern sections. The Nautile, best known for finding the wreckage of the Titanic, previously discovered two cracks in the stern and at least four in the bow where the two pieces came to rest some 130 nautical miles (240 km) west of Spain's coast. Three more cracks have appeared in the stern, Deputy Prime Minister Mariano Rajoy told a news conference yesterday. Now we have to evaluate how much fuel could be escaping into the sea and if there is a chance of it solidifying. A team of scientists had been formed to study the data. Rajoy previously said the government was hoping the fuel oil would congeal at near freezing seabed temperatures, only to discover that the thick sludge was escaping. Most of the fuel oil, an estimated 60'000 of the 77'000 total tonnes, went down with the ship. A barrage of oil slicks continued to menace the Galician coast, with Portugal and France on the alert for any pollution coming their way. Portugal yesterday hired a Norwegian rig to suck up spills from the Prestige, joining a fleet of vessels hired by Spain to scoop the smelly black slicks from the sea. Thousands of Spanish military personnel and volunteers were busy scrubbing sludge from the rugged coastline.