Some 2,000 haemophiliacs died after British doctors tested new blood products on them, having ignored safety warnings for the sake of “scientific kudos,” it has been claimed.

From the early 1970s to the mid-1980s, 4,500 haemophiliacs were exposed to lethal viruses. Around 2,000 have since died of Hepatitis C or HIV, the BBC’s Newsnight programme said.

The report last night claimed many were infected by supplies of the clotting agent Factor 8 from abroad, and said much of this plasma came from donors such as prison inmates in the US.

Successive governments claimed not enough was known about the dangers of Factor 8 concentrates to stop using them in time, and crucial documents had “mysteriously disappeared,” the programme said.

One was a letter from the head of Britain’s public health surveillance centre warning about the risk of Aids.Victims and their relatives have obtained papers suggesting many people knew a lot more, a lot earlier, than has been disclosed.

The report was broadcast hours before the opening today of the first hearing of an independent public inquiry into the affair.