IT is the largest treatment disaster in the history of the National Health Service, almost 3000 people have died and 50,000 more may have been infected after receiving contaminated blood products. But it’s a disaster foretold, involving an alleged cover up, a scandal in which haemophiliacs were the principal victims, young women were unknowingly infected by their husbands, patients who needed blood after surgery also picked up lethal viruses, where medical records have gone missing and government documents have been destroyed.

It begins with 4,689 haemophiliacs in the 1970s and 80s who were given contaminated blood products by the NHS, around 90% of whom contracted HIV and Hepatitis C. Almost 3000 of them have now died.

Haemophilia is a genetic condition that causes a lack of the essential blood-clotting protein known as factor VIII, where even a small injury can result in dramatic blood loss and death. In the 1960s, a frozen blood product called cryoprecipitate was introduced, which could stop bleeding, but could be administered only via transfusion, in hospital, and because it was produced from a small number of donors, it was always in short supply.

In the 1970s what appeared to be a dramatic breakthrough and a life-saving solution emerged with the mass production and freeze-drying of factor concentrates made by distilling the plasmas of a large group of donors. Haemophiliacs were able to keep a bottle containing factor VIII in the fridge and self-inject.

However British laboratories were not able to keep up with demand and, in 1973, began importing blood plasma from the US, much of which came from drug addicts, prostitutes and prisoners infected with HIV and Hepatitis C. The US donors were paid and many of those who most needed the money were likely to have infected blood.

Factor VIII concentrate was initially produced in 1966, more than a decade before the first Aids case was diagnosed, but as early as the 1950s, experts had warned of the risk of hepatitis from mass-produced blood products.

In 1974, American scientist Judith Graham Pool – who had discovered cryoprecipitate – described the payment of blood donors as “dangerous” and “unethical”. The World Health Organisation warned the UK not to import blood from countries that paid donors and had a high incidence of hepatitis, such as the US. In 1975 a Granada World in Action programme revealed that contaminated blood was being harvested on “skid row” and questioned why Britain was not producing its own factor VIII concentrate.

But still haemophiliacs continued to receive the tainted blood.

By 1983, according to minutes form the Committee on the Safety of Medicines, Government scientists and civil servants knew that those receiving the clotting agent were at risk of Aids. It was recommended that it should all be heat-treated to kill viruses, but implementation was delayed because of the cost.

The most serious warning came in May 1983 from Dr NS Galbraith, director of the Communicable Disease Surveillance Centre in England and Wales. He wrote a paper for the Department of Health and Social Security, which concluded: “All blood products made from blood donated in the US after 1978 should be withdrawn from use until the risk of Aids transmission by these products has been clarified.” But they were not withdrawn. The Department of Health considered his advice “premature”.

In 1984, the US Food and Drug Administration banned medical use of blood from high-risk groups including prisoners. But the British Department of Health continued to import US blood.

And the UK was still denying, in the face of overwhelming evidence, the blood-borne infections. Six months after the Galbraith warning the then health minister Kenneth Clarke told the House of Commons, “There is no conclusive evidence that Aids is transmitted by blood products.”

In 2008 Nicola Sturgeon, then health minister, set up an inquiry under Lord Penrose into the tainted blood scandal, which was to cost £13 million and report seven years later. Dr Mark Winter, giving evidence to the Penrose, refuted Clarke’s [1984] statement, saying “all haemophilia clinicians by this stage clearly believed that commercial blood products could and were transmitting Aids”.

It wasn’t just haemophiliacs who were infected, other patients were also given transfusions, but from a single donor rather than many – up to 20,000 for the US imports – although the infection rate was as low as 1%.

In 1989 the Hepatitis C virus was first identified, with the result that up to then the damage inflicted did not usually show until the liver began to fail, so most did not know until that happened they were infected. Many still do not.

In 2000 the Department of Health was forced to admit that crucial records had been destroyed, blaming “an inexperienced member of staff”. In February this year it emerged that 450 files had also been taken from the archives by staff and not returned.

The Penrose inquiry eventually reported in 2015, but was widely dismissed as a whitewash, no blame was apportioned and the sole recommendation was that all those who had received a blood transfusion prior to 1991 should have a blood test for hepatitis C.

Jason Evans, whose father died in 1993 having contracted hepatitis and HIV, runs the Factor 8 campaign group. He said, “People are sick and dying, families are dealing with severe bereavement but the Government refuses to accept its clear liability and pay compensation." Adding that it was offering only “means tested scraps” and that if the Government wanted to “do the right thing they will provide a statement accepting their liability now.”

The Infected Blood Inquiry opened in London on Tuesday and has been hearing from victims. It is chaired by former High Court Judge Sir Brian Langstaff. It will move to Edinburgh in July to hear further testimony, from July 2 to 5 and July 8 to 11.