Days after she led 5,000 people in a protest against the pipeline plan in 2006, President Vladimir Putin ordered it to be rerouted away from the lake. Now, her role has been recognised with an international award from green activists.

At a ceremony on Sunday in San Francisco, Rikhvanova was presented with one of six annual Goldman Environmental Prizes -- an award some campaigners call the Nobel prize of grassroots environmental activism.

"Of course I didn't do it all myself," Rikhvanova told Reuters by telephone as she travelled to the awards ceremony.

"Greenpeace and WWF and other organisations all helped. But we had to do something locally too."

David Gordon, head of the environmental group Pacific Environment, which nominated Rikhvanova for the award, said she was being too modest.

"She really deserves this award," he said. "WWF, Greenpeace and Pacific Environment would not have been able to do this alone. It needed somebody to say 'I am local' and to stand up and take action."

CONTAMINATION RISK

Russian pipeline monopoly Transneft is building the multi-billion-dollar pipeline to supply Siberian crude to energy-hungry China and Japan. The original route had it skirting 400 metres (yards) from the lake's northern shore.

Environmentalists said a leak from a pipeline so close would have a disastrous impact on the lake.

Environmentalists credit the Irkutsk protest with persuading Putin to tell Transneft to switch course away from Lake Baikal.

Victories for civil society against big business in Russia are rare but Rikhvanova's was clear -- she had helped persuade Putin to back local activists against Transneft.

Rikhvanova trained as a biologist at the university in Irkutsk and in the 1990s set up the Baikal Environmental Wave group of local activists.

Her activism has come at a cost. Police have raided Rikhvanova's offices and last year young men armed with clubs attacked activists camping near a planned uranium plant. The attackers killed one of the activists.

Police later detained Rikhvanova's son, and accused him of being one of the attackers. He has denied acting violently. His mother says the charges against her son are part of a elaborate campaign to compromise her work.

The Goldman Prize comes with $150,000 that Rikhvanova said she will use to finance future campaigns.

She said she has a lot more work to do to protect Lake Baikal. Rikhvanova is building support against a Soviet-built pulp mill on the southern shores of the lake that has spewed toxic waste into the lake since opening around 40 years ago.

The planned nuclear plant, also in the region, will take deliveries of uranium from around the world, enrich it and then ship the fuel to atomic power stations in other countries.

"We have a lot to do and must keep going," Rikhvanova said.