JAKARTA (AFP) - Indonesia will not share bird flu samples with the World Health Organisation until a dispute with the UN body is resolved in "black and white," the nation´s health minister said Wednesday.

Health Minister Siti Fadilah Supari made the comments one day after reports that Indonesia was not honouring its promise to resume sharing samples with the WHO for tests aimed at fighting the deadly disease.

Indonesia agreed in March to an immediate resumption, after reaching a breakthrough agreement in international talks with the WHO to develop a new mechanism on sample-sharing.

But more than four weeks later, samples have not been sent.

Supari said although WHO guarantees had been given orally, Indonesia wanted them in writing, and would now await the outcome of the World Health Assembly, an annual meeting of WHO members in Geneva, later this month.

"Diplomatically, the guarantees have been made, but we want it in black over white, in writing," Supari told AFP.

"So far we have not seen concrete assurances, but we will still have to wait until after the WHA (World Health Assembly) later this month," she said.

"Then, we will see," she added.

Indonesia, the country worst hit by the virus with 74 human deaths, stopped sending samples in December over concerns that drug firms would use them to develop costly vaccines beyond poorer countries´ budgets.

But firms now need permission from a country for access to its virus samples under the March agreement.

Sample-sharing is said to allow experts to track the evolution of the disease and determine which strains have become drug resistant, in an attempt to better tackle the virus.

Scientists fear bird flu´s deadly H5N1 strain, which was first reported in humans in Hong Kong in 1997, could mutate into a more infectious form and spark a flu pandemic with the potential to kill millions worldwide.

The H5N1 strain of bird flu has killed at least 172 people since 2003, mainly in Southeast Asia, according to the WHO.

Indonesia currently has 20 people infected with bird flu receiving treatment in hospitals.

Most human infections have been blamed on contact with sick birds.