Described as a "Noah's Ark" of plant life by the Norwegian government, which funded the project, the Svalbard Global Seed Vault will preserve around three million seeds representing all known varieties of the world's crops.

The seeds will be hidden in a heavily fortified vault in Norway's Svalbard islands, a remote archipelago about 1,000 km (620 miles) from the North Pole.

The seeds will be stored at a temperature of -18 Celsius (-0.4 Fahrenheit), in order to ensure their survival for hundreds, even thousands, of years.

The project is supported by the United Nations Food and Agriculture Organisation and is expected to open in September 2007.

Natural guardians

The independent Global Crop Diversity Trust, which is helping to run the project, said that crop diversity is already at risk by accidents, mismanagement and budget cuts.

"This facility will provide a practical means to re-establish crops obliterated by major disasters"

Cary Fowler, executive secretary of the Global Crop Diversity Trust

"This facility will provide a practical means to re-establish crops obliterated by major disasters," said Cary Fowler, executive secretary of the trust.

About 1,400 seed banks around the world already hold samples of the world's crops, but the Norwegian project is thought to be one of the first international efforts.

The trust also said that the Svalbard islands proved a perfect place to construct such a project, in part because of the many polar bears roaming the vicinity which can act as natural guardians.