The city had been running a pilot project since November.

'After the pilot run, the dredged area became deeper and cleaner while doing no harm to turtles,' said Professor Ha Dinh Duc, the project's chairman. 'That is why we decided to buy this technology.'

Hanoi's Hoan Kiem Lake at the heart of the old city is stagnant, thick with green algae, choked with sludge and full of fish and crabs. It is also a historical treasure and the heart of Vietnamese nationalism.

But most importantly, the lake is home to Vietnam's most famous turtle. The turtle might be the last of a unique species, Rafetus leloii, or belong to another critically endangered species, Rafetus swinhoei, of which only three others are known to exist in Vietnam and China.

Crowds gather at the lakeside when the turtle is spotted, hoping to catch a glimpse of its head for good luck.

Le Xuan Rao, director of the municipal Department of Science and Technology, said negotiations were being held on acquiring the technology.

Vietnam plans to ask German experts to help train staff on the use of the SediTurtle, a robotic sediment collector, to dredge the lake's 114,000 square metres in January 2010, Duc said.

He did not disclose the price, but the state-run Tuoi Tre newspaper on Wednesday quoted Rao as saying it might cost more than 430,000 dollars.

The pilot project has been financed by Germany's Ministry of Research and Education in collaboration with Vietnam's Ministry of Science and Technology.

Deutsche Presse Agentur - December 24, 2009