Work on the world's longest oil pipeline has been suspended after scientists protested that it would cause severe ecological damage.

The 4,187-kilometre pipeline from Siberia to the Sea of Japan was hailed by the Russian Government last year as the nation's biggest infrastructure project and one that would revitalize Russia's far east and make it one of the biggest oil suppliers to other countries.

But the project is now mired in controversy after the Russian environmental watchdog ordered a halt to work under way within a mile of Lake Baikal, the world's oldest and deepest lake and a UNESCO World Heritage Site.

Oleg Mitvol, deputy head of the Natural Resources Ministry's Environmental Oversight Agency, said: "We have environmental legislation and we will demand that it is obeyed. There should be a pipeline but it should not spoil the world heritage of Lake Baikal."

The Ministry also said that a planned oil terminal could threaten Russia's only marine reserve and its oldest nature reserve, which is home to the Amur leopard, arguably the world's rarest big cat.

The official protests are a rare victory for environmental groups that have been campaigning for Transneft, the state pipeline monopoly, to change the planned route.

Roman Vazhenkov, of Greenpeace Russia, said: "However ignorant Transneft is of public opinion, Russia does not want an international scandal." Transneft could ignore the protests, but might then have trouble raising loans.

In December the government approved the plan to build a pipeline from Tayshet, in western Siberia, to Perevoznaya Bay, by the Sea of Japan, to service Asian markets during the next decade.

Construction was due to start this summer and the first section, from Taishet to Skovorodino, near the Chinese border, was to be ready by 2008.

The first controversy was over the decision to build an oil terminal at Perevoznaya, a pristine bay, rather than expanding the terminal at the nearby port of Nakhodka, as planned.

Environmentalists say a new terminal would threaten a UNESCO Biosphere Reserve, which is home to the world's last 30-35 wild Amur leopards.

Sarah Christie, carnivore programme manager at the Zoological Society of London, said that the noise, the roads and the influx of people "could be the last straw for the leopard."

Perevoznaya is also next to Russia's only marine reserve, and the Russian Academy of Science estimates that the risk of a tanker accident is 17 times higher there than at Nakhodka.

Sergei Bereznuk, of the Phoenix Fund environmental body, said: "Transneft says Perevoznaya is the best option, but no one knows how it decided that."

Critics say that Sergei Darkin, governor of the far eastern Primorye region, had the route changed because he had financial interest in Perevoznaya. He denied that and said a final decision on the route had not been made. "All I can tell you is that the pipeline will be built ... and will bring huge economic benefit," he said.

Sergei Grigoriev, the vice-president of Transneft, denied any wrongdoing and said that a contractor was simply doing a feasibility study. "We are doing everything according to Russian law," he said.

Source: China Daily