Ms May would not have heard it, but on the other side of the world Mr MacKenzie jumped up and celebrated the news.

“It was the best birthday present she could have given me because this is massive for Australia. This is huge. This is going to be a warts and all investigation of one of the UK’s greatest health scandals and they’ve only got one-third of the victims we had in Australia,” Mr MacKenzie said.

“After all these years of fighting the Australian Government, they’re going to have to pay attention now. And we need nothing less than a judicial inquiry here.”

Ms May ordered a “Hillsborough-style” inquiry into how at least 2400 people in Britain died from hepatitis C and Aids-related conditions after receiving transfusions of government-supplied imported blood products in the 1970s and 1980s, and thousands more were left with permanent and crippling conditions.

(A 2014-16 inquiry into the Hillsborough stadium soccer disaster in 1989 in which 96 people died looked at the deaths and evidence of a cover-up of negligence and failures by authorities.) 

Ms May’s decision this week followed years of campaigning by “tainted blood” survivors and their families, an unprecedented letter by the leaders of all the UK’s opposition parties calling for an investigation, and a stunning threat by the former UK health secretary who oversaw the “tainted blood” period, Andy Burham.

Mr Burham used his last speech as an MP to demand a public inquiry into “tainted blood”, and warned that if Ms May failed to act he would hand police a dossier of evidence on July 26 he claimed would expose “a criminal cover-up on an industrial scale”.

Mr MacKenzie said up to 20,000 Australians – including babies, children, women after childbirth and haemophiliacs – are believed to have received “tainted blood” transfusions in the 1970s, 1980s and 1990s.

An unknown number died and others developed, or could develop, serious liver disease, liver failure or liver cancer, at a rate “generally much higher” than people who contract the condition by other means, primarily illicit drug use, a Senate inquiry in 2004 was told. 

The inquiry recommended the federal and state governments issue an apology to “tainted blood” hepatitis C victims, establish a financial fund for victims and provide “case managed” support for people affected.

It didn’t happen, said Mr MacKenzie, of Dora Creek, and Medical Error Action Group founder Lorraine Long.

For the past three years the two have written to Australian health ministers asking for figures of the number of Australian “tainted blood” victims contacted by the Australian Red Cross Blood Service Lookback programme.

“We don’t even get responses,” said Ms Long.

Parliaments in Canada, Ireland, Japan, New Zealand, the United Kingdom and Scotland have issued formal apologies to “tainted blood” victims in the past five years.

Former UK Prime Minister David Cameron said in March, 2015: “It is difficult to imagine the feelings of unfairness that people must feel at being infected by something like hepatitis C or HIV as a result of a totally unrelated treatment, and to each and every one of those people, I would like to say sorry on behalf of the government for something that should not have happened.”

In Scotland in 2016 the government agreed to pay immediate compensation payments to victims, with lifetime pensions. 

“In Australia there’s been silence,” Mr MacKenzie said.

After Mr Cameron’s apology Ms Long wrote to then Australian Prime Minister Tony Abbott, asking what had happened to the Australian response.

The letter was referred to then Health Minister Sussan Ley.

In September 2015 Ms Ley wrote: “I wish to restate that I am deeply sorry to learn of the personal and physical suffering experienced by those who acquired hepatitis C from blood transfusions”, and the government acknowledged “the significant burden of this disease including the stigma”.

The response angered Mr MacKenzie and Ms Long, who called the failure to apologise and provide “case-managed” support for “tainted blood” victims a national disgrace.

“How can the UK apologise for a medical disaster, and Australia can’t, even after its own Senate recommended an apology?” Ms Long said.

An apology was vital for many reasons, including an acceptance of responsibility by federal and state governments, she said.

“People affected by one of Australia’s worst medical disasters can begin the important process of being able to show loved ones, employers and treating doctors that their infections were the outcome of an appalling tragedy and not the result of any illicit activity such as taking drugs.

“An apology will go some way to removing this ugly blood stain on Australia’s record.”

A 2004 Senate inquiry heard devastating evidence from victims who received hepatitis C in blood transfusions during childbirth and suffered debilitating symptoms, but did not discover the condition until years later. In at least one case a newborn baby was infected by hepatitis C because of a “tainted blood” transfusion.

“It’s the great unmentionable - how governments knew people would be infected with hepatitis C if they were given blood transfusions, but people weren’t told, and screening tests that could have been done, weren’t,” Mr MacKenzie said.

“Blood services were extremely aware there was a virus being transmitted to people, but they chose to do nothing about it. They just destroyed people’s lives.”

The Senate inquiry was told a screening test for hepatitis C was available from 1986, but only Queensland blood services used it.

It was not until February 1990 that a hepatitis C screening test was used in other Australian states.

Haemophilia Foundation Australia (HFA) told the Senate inquiry it appeared “issues such as test sensitivity and specificity, cost and fears about reduced blood supply were considered more important than the seriousness of hepatitis”.

The Australian Red Cross Blood Service said the level of blood donations in the late 1980s was a “major concern”, and up to five per cent of donations might have been rejected if the screening test was applied.

The Senate inquiry heard Federal and state governments, health departments and blood services across Australia knew some blood transfusion recipients would be infected with hepatitis C without the screen tests.

“The blood services were extremely aware there was a virus that was being transmitted via blood transfusions, but they chose to do nothing about it,” Mr MacKenzie said.

“So many of the cases were women who had blood transfusions after birth.”

Many were not aware they had been infected with hepatitis C until years later. Many suffered from serious and debilitating symptoms for long periods without knowing they had a serious viral condition.

The inquiry heard evidence from angry witnesses who had not been contacted by the Australian Red Cross Blood Service about their infections. Others expressed shock when they were advised by a letter from the Red Cross that they had hepatitis C.

“It was evening when I opened the letter and I couldn't call (for help) until the next morning. I found it hard to believe this was something they would tell you by mail, or that they would tell you by mail and not include some information about the virus,” one “tainted blood” victim told the inquiry.

Others told how a hepatitis C diagnosis had made them outcasts in their own families because people believed they had contracted the virus through illicit drug use.

“My brother and sisters who are Catholics have shut all doors on me. I am an outcast. They don’t want to know,” one witness said.

“It is the little acts that occur within the family unit, that suddenly take on a more sinister meaning in the face of hepatitis C infection. Sharing razors, accidentally using someone’s toothbrush, your four year old putting a band-aid on your cut and kissing it better, the way you have done for him. You wonder at what point you may have compromised the safety and well being of those you care about the most.”

The Senate inquiry found there was evidence to suggest relevant authorities in Australia could have instigated surrogate testing before 1990, but “based on the information available at the time, it was open to the relevant authorities to take the decisions they did”.

Mr MacKenzie said the “tainted blood” issue was “first and foremost, a human tragedy that has destroyed the lives of many men, women and children”.

“Suffering of the greatest magnitude is being endured by people whose only mistake was to place their faith in the managers of Australia’s blood supply,” he said.

Mr MacKenzie said the UK inquiry would expose how authorities failed individuals who received blood transfusions, and failed again by covering up.

“I’ve done my level best for the last three years to get figures on how many Australians have been affected and contacted by our government, but the government refuses to respond.

“We have to ask the question – how is it that the UK, with less than a third of the victims we have in Australia, recognise the need for a warts and all inquiry, but in Australia we’re basically doing nothing.”