Mark Stewart implored the Infected Blood Inquiry to investigate “why he was given contaminated Factor 8 when it was not necessary” by doctors at the Royal Free Hospital in Hampstead.

In a moving statement read by his daughter Jade on the third day of the inquiry’s preliminary hearings, Mark made a plea to find out why he had been used as a “guinea pig” and also detailed the devastation wreaked by contaminated blood products on his family.

His father and brother – both called Angus – died after complications following products given to treat von Willebrand disease, which is caused by a lack of clotting agent.

Mark, who suffers from moderate von Willebrand disease, said: “I was given contaminated Factor 8 on May 12, 1981, as an 11-year-old boy. I have learned from my medical records that I did not require this treatment. I was a previously untreated patient, or guinea pig.

“I contracted hepatitis C and was exposed to other fatal diseases. But despite this being known to my treating clinicians, I did not find our until 2007, more than 25 years later.”

Shortly after Mark’s statement was read, a lawyer representing the government apologised to the victims of the scandal.

Eleanor Gray QC, representing the Department of Health and Social Care, told the inquiry: “I say unreservedly that we are sorry. We are sorry that this should be so, that this should have happened when it should not.”

The hearing also saw lawyers for more than 600 affected individuals criticise the Treasury for asking for Cabinet Office for guidance on how to respond to Freedom of Information requests made by campaigner Jason Evans.

Des Collins, of Collins Solicitors, said: “It is outrageous and wholly inappropriate, but sadly [not] unexpected.

“It is not for government departments to ask the Cabinet Office to decide which documents can be made available to whom and when. A Freedom of Information request of this nature should not be granted at a civil servant’s discretion.”

A spokesperson for the Treasury said: “We will sometimes consult with other relevant departments to seek their views on disclosure for particular requests. “This is to ensure that information is dealt with in an FOI-compliant way and is not inappropriately withheld or disclosed.”