Malaysian environmentalists slammed a billion-dollar undersea cable project, saying it is unsafe because of earthquakes in the region.

Friends of the Earth Malaysia said tectonic plate movements in the past two years around Asia had seen a spate of earthquakes, and called for plans linking the Bakun hydro-electric dam on Borneo island to the mainland to be dropped.

The group's honorary secretary, Meena Raman, cited the December earthquake off Taiwan that damaged undersea cables and disrupted communication across Asia, as an example of the possible dangers.

The Taiwan quake "shows that we are dealing with an ecosystem that has changed since the undersea cables were first mooted years ago," Raman told AFP .

"There is fundamentally a need to reassess the viability and also the safety of these undersea cables," she said.

The US$2.5 billion cable project was dropped after the 1997 Asian financial crisis, but Malaysia's energy minister Lim Keng Yaik last week said it was now back on course to be completed by 2012.

Raman said the group was calling for a new Environmental Impact Assessment (EIA) to be done after the years of delays.

"There ought to be a new EIA done because of the changed circumstances. The government cannot rely on the old EIA which was approved years ago," she said.

Under the project, about 700 kilometres of transmission lines and 670 kilometres of undersea cables will have to be installed.

Friends of the Earth said the cables would weigh 60 kilogrammes per metre, giving a total weight of at least 40,200 tonnes per cable.

"Common sense tells us, given the massive structure, one cannot ignore the impacts such a structure would have," said Raman.

The government is trying to generate cheaper hydro-electricity to diversify Malaysia's energy mix from a dependence on natural gas and fossil fuels to renewable energy sources.

The Bakun dam, which involves flooding an area the size of Singapore, has attracted fierce criticism because of its harmful impact on the environment and the fact that 10,000 residents have already had to evacuate the project site.