It has long been suspected that China may have fudged the numbers when it comes to the true number of coronavirus infections the country endured.
But there now appears to be proof that during a critical phase of the pandemic up to 10 times more people caught Covid-19 than official figures stated. Extraordinarily, this revelation has come from the Chinese government itself.
An infectious diseases expert has said authorities failed to give a "true appreciation of the infection and its size".
From late January, images of Wuhan being locked down circulated globally, a precursor of what was to come in any countries.
According to the Wuhan Municipal Health Commission, the city where coronavirus was first recorded has seen a total of 50,354 cases in its more than 11 million residents.
However, newly released research by the Chinese Centre for Disease Control and Prevention (CDC) paints a very different picture.
It tested 34,000 people within Wuhan, the surrounding Hubei province and a number of other cities outside the area, to see if they had antibodies to Covid-19 – a sign that they would have contracted the virus.
"The investigation found that the positive rate of new coronavirus antibodies in the community population in Wuhan was 4.43 per cent," the report stated.
They would suggest almost 500,000 people in Wuhan contracted Covid-19, 10 times more than the 50,000 officially recorded.
Outside of Wuhan, the number dropped dramatically, with just two people in the study from the wider Hubei province having the antibodies.
"The survey results show that the (Chinese) population is generally at a low level of infection, indicating that the epidemic control with Wuhan as the main battlefield has been successful and effectively prevented the large-scale spread of the epidemic," the CDC stated.
Wuhan numbers massively under-reported
China watchers have said the vast under-reporting of the true number of cases is likely down to a number of factors. These include a lack of testing kits which meant many people with Covid-19 symptoms were never diagnosed as positive. This was not only an Chinese issue – in the early days of the pandemic many countries struggled to keep up with demand for tests with cases slipping through the net.
But in China, there are also appeared to be a concerted effort to downplay the virus' spread both to calm the public but also, it has been suggested, because of the bloated nature of the Xi Jinping-led Chinese government and the desire not to offend higher up officials.
A CNN report from earlier this month found that, for a time, officials in Wuhan routinely minimised the number of coronavirus infections in figures given to the public.
On February 10, 2478 new cases of Covid-19 were officially recorded in Hubei, including Wuhan. However, a leaked confidential document seen by the US network showed that the true number was 5918 new cases, more than double.
The infections that were brushed under the carpet were what Chinese officials called "clinically diagnosed" cases. These were cases that were very likely to be Covid, and showed classic symptoms, but the patient hadn't had a test. In some cases, the patient was seriously ill and being treated as if they had the disease, but they didn't appear in the numbers.
These "clinically diagnosed" cases were often lumped into a category called "suspected cases" which were often reported on many days later or simply added to a running tally that didn't list daily new infections. Critics have said this may have been an attempt to make the outbreak look more contained.
Talking to CNN, infectious diseases expert Professor William Schaffner of Vanderbilt University in Nashville said Chinese officials had "seemed actually to minimise the impact of the epidemic at any moment in time. To include patients who were suspected of having the infection obviously would have expanded the size of the outbreak and would have given, I think, a truer appreciation of the nature of the infection and its size."
It was only later in February that the definition of a Covid-19 infection was widened in China to include these cases.
Communist Party pecking order
A further factor was the Communist Party's strict and complicated political hierarchy when it came to decisions about how to handle the pandemic
That was one of the conclusions reached by Richard McGregor who analysed China's reaction to Covid-19 in a paper for Australian think tank the Lowy Institute.
"The CDC ranks below the National Health Commission, whose leaders in turn fall under provincial party chiefs in the bureaucratic pecking order," McGregor wrote in July.
"The city and provincial leaders needed permission from the top of the party and central government in Beijing to make announcements of any gravity."
McGregor also said officials in Hubei may have been keen to avoid announcing a deadly new virus during the Lunar New Year – an important and politically sensitive time.
"The entire system, beset with fear, uncertainty, cover-ups, bad faith, and indecision at multiple levels, misfired until the top tier finally realised the gravity of the situation," he wrote.
"The result was that the virus spread beyond Wuhan, into the rest of the country, and then the world — further, and faster, than it ever should have."
The CDC's findings chime with a June US analysis that also suggested infections were far greater than reported.
Academics at the US Washington University School of Medicine in St Louis couldn't test Wuhan locals for antibodies. Instead they examined the distribution of funeral urns and the capacity of cremation services in the city during the pandemic's early months.
The non-peer reviewed paper said Covid-19 deaths were likely to be in the region of 36,000, more than 10 times the reported 2500 fatalities. As such, infections were also likely to be at least 10 times higher.
"The magnitude of discrepancy between our estimates based on cremation related data and Chinese official figures in early February, suggests the need to re-evaluate official statistics from China," the US analysis said.
There are still some who doubt the veracity of China's Covid-19 figures. It can seem incredible that a vast nation where coronavirus first appeared should now be almost entirely free of it, bar flare ups here and there.
However, since earlier in the pandemic, China has tightened up and standardised its Covid-19 reporting. Research from Oxford University has concluded that while early figures were "manipulated", current numbers appear genuine. And if the virus was rife right now in the country, it would be difficult to hide neighbourhoods being locked down and rising hospital admissions.
Nonetheless, official numbers emanating from Beijing – on everything from industrial output to GDP – have long been taken with a pinch of salt abroad.
It's claimed there are strong motives for officials to ensure targets are met, or appear to be met, for fear of embarrassing the Communist Party and their superiors.
The admission that Covid-19 infections in Wuhan could have been 10 times the official figure may lead some to believe China's experience with Covid-19 will never completely add up.