Cutter Biological continued to dump stocks of the factor VIII blood-clotting agent for haemophiliacs on poor countries for nearly a year after introducing a safer alternative, the report in the New York Times said.

It happened in the early 80s, after the Centres for Disease Control in Atlanta, Georgia, reported in July 1982 that haemophiliacs were becoming ill from blood products.

Up to that time factor VIII, produced from the plasma of about 10,000 donors, was not screened for HIV, and it became a leading killer of haemophiliacs in the early years of Aids.

Yesterday Bayer, which has paid out $600m (£375m) to settle lawsuits brought by thousands of American haemophiliacs, insisted it had "always behaved responsibly, ethically, and humanely".