Huan said Agifish has been using the fuel, made from fat left over from processing, to run pumps at its fish ponds in the Mekong Delta province of An Giang in southern Vietnam.

"The fuel is as good as diesel oil," he said.

He said samples of the catfish fuel had been sent for tests at laboratories in Ho Chi Minh City for quality checks and government approval.

The state-run Tien Phong (Vanguard) newspaper on Monday quoted Ho Xuan Thien, the chief engineer of the project, as saying the firm planned to build a 10,000-tonne-per-year factory in 2007 to mass produce the fuel for domestic markets.

Thien said a kilogramme of catfish fat could produce 1.13 litres of biofuel.

Vietnam produces around 30,000 tonnes of catfish annually, mainly for exports to the United States and Europe.

Agifish's products range from canned catfish through pre-cooked breaded fillets to sweet-and-sour fish prepared in clay containers. Although Vietnam is Southeast Asia's third largest crude oil producer after Indonesia and Malaysia, it still relies on oil product imports for fuel because it lacks major refineries.