HAMBURG, Germany (AFP)
A chemical tanker that sank in the port of this northern German city has already leaked about half the 980 tonnes of sulphuric acid it had on board, its owner said. The managing director of the ship's proprietor Norddeutsche Affinerie told reporters that more of the poisonous substance had spilled into the harbor than previously thought.

The sinking late Monday of the German ship ENA-2 after collision with a container ship during docking has caused fears of a major environmental accident. Authorities have opened a criminal probe against the captain on charges of water polluting and endangering ship travel after a blood test showed that he had been drinking heavily.

The managing director of the ship's proprietor said that water tests showed the effect on the Elbe to be "relatively small" and that fish in only a small part of the harbor had been killed by the leak. But Greenpeace said the impact could be sizeable. "The Hamburg petroleum port may well be biologically dead after this accident," said a spokesman for the environmental watchdog, adding that far more than the estimated 1,000 fish had been killed as a result.

Some 430 tonnes of a mix of water and sulphuric acid are still in the hull of the stricken 62-meter (200-foot) vessel, which the managing director of the ship's proprietor said could have a corrosive effect on the steel walls of the tank. A fire brigade spokesman said that it would now be "too dangerous" to pump out the tanks while the ship is still underwater due to the potential for an explosion. Rather, a giant crane will be used to move the vessel before the extraction of the liquid begins. "Then we need to lift it, turn it and put it on its feet," the fire brigade spokesperson said, adding the process would take several days.

Earlier Thursday, businesses in a wide radius were told to shut their doors and windows while a crane lifted the ship slightly. The delicate operation went off without incident. Eleven people including nine port employees and two police officers were admitted to hospital after the accident for breathing in toxic fumes.