Indonesia, the nation hardest hit by bird flu, sent 15 virus samples from two people who died of bird flu to WHO last month, the first such transfer since August 2007.

WHO spokesman Gregory Hartl confirmed in an email to reporters from the body's Geneva headquarters that the samples had not shown any signs of mutation.

Scientists fear a human-to-human mutation of the virus would kick off a worldwide pandemic that could kill millions.

Health Minister Siti Fadilah Supari said the samples had been sent out of 'goodwill.'

WHO had warned last year that Indonesia's reluctance to share flu samples put its own population at risk because any vaccines developed would not be designed to combat Indonesian strains of the H5N1 virus.

Indonesia had halted sharing samples in December 2006, saying it feared multinational drug companies could use them to develop vaccines that were not affordable for poor countries.

In August last year, a sample of the bird flu virus that killed a woman on Bali was sent to a World Health Organisation laboratory to allay fears that there had been a human-to-human transfer.

H5N1 is endemic across nearly all of Indonesia, where humans and poultry live in close contact. Of the 105 overall deaths reported since the disease emerged here, 11 have occurred this year. -- AFP