A pharmaceutical company involved in the contaminated blood scandal claimed there was “little evidence” of the risk of AIDS transmission through its products, despite concerns.

The Infected Blood Inquiry heard evidence on September 29 from the former Revlon Healthcare company Armour, one of the US pharma companies that sold infected blood products to the UK throughout the 1970s and 1980s.

The US Centers for Disease Control and Prevention was investigating the possible relationship between AIDS and the use of blood and blood derivatives in 1983.

In a letter to all Haemophilia Centre Directors in 1983, Armour wrote: “The Armour Pharmaceutical Company is acutely aware of the current concern of the medical world regarding AIDS and its possible implication to haemophilia care and treatment.”

The company claimed to have a program in place to prevent using plasma from high-risk subjects, "despite the fact that there is a little evidence to associate plasma component therapy with the transmission of AIDS”.

Evidence showed that up to 20,000 donors were pooled to make their products, a high-risk practice.

Armour withdrew Factorate and High Potency Factorate, their blood products, from the market in 1986.

The inquiry also heard evidence of correspondence in 1983 between Armour and Dr Peter Kernoff, director of the Haemophilia Reference Centre at the Royal Free, who requested financial support for AIDS research at the Royal Free.

The project would focus on the "effects of blood products on the immune system of patients with haemophilia", wrote Dr Kernoff.

“The causes of these [immunological] abnormalities are unknown, but may include transmission of a previously unrecognised virus or other agent.

“However, the possibility that infusion of essential therapeutic products may be complicated by very serious hazards is causing extreme concern amongst patients and those responsible for their care.”

Jason Evans, founder of Factor 8 campaign, said: "My father received Factorate throughout 1983 and 1984, long after Revlon Healthcare knew the risks.

“It's shocking to see today the extent of just how much they knew and how early on. I just can't believe they carried on selling these products after knowing these risks.

“My father first tested positive for HIV in November 1984 and I have little doubt from this evidence that had these companies made users aware of the risks, or better yet, withdrawn products they knew to be dangerous, my father and many others would still be alive today."