They are called the “daily death figures” – and they provide one of the starkest illustrations of the devastating loss of life caused by Covid-19.

Over the course of the pandemic this sobering dataset, issued every 24 hours by NHS England, has given real-time statistics on the number of people with coronavirus dying in hospitals.

For journalists, politicians and the wider public, the rising death toll has formed a vital part of our understanding of the severity of the pandemic over time.

It has also informed vital policy decisions, such as when lockdowns should be lifted.

But something unusual is happening to a small number of deaths in the data. These rare cases aren’t being reported to the public until much, much later than they occur – in some cases, up to nine months on.

The lag in reporting has effectively resulted in deaths from the first wave of the pandemic being logged during the current second wave.

And no one seems to know why it is happening.

Deborah Coles, director of the charity Inquest, threw the question back to us: “Is it just because the system is overwhelmed and it’s not coping?

“It would be good to try and get some questions answered as to why that is.”

Everyone we spoke to had different suggestions ranging from delays issuing death certificates to admin errors as hospitals work under phenomenal pressure.

But the NHS’s own guidelines state that these deaths should be reported onto its live-tracking system within 24 hours. The data collection process is meant to be straightforward. So what could possibly be taking nine months?

The system

The story of how the Covid-19 daily death figures came into existence is fascinating in its own right. 

In March 2020, in the early days of the pandemic, NHS chiefs had identified there was a need for timely data on coronavirus deaths and the Covid-19 Patient Notification System (CPNS) was built in just five days by a company called Arden & GEM, working with the NHS.

The firm had a track record of building similar reporting tools for deaths in custodial settings.

The bespoke IT system replaced a manual data return spreadsheet which hospital trusts were previously using over email, as a temporary measure, to record deaths.

As soon as the system was up and running hospital trusts began entering information about each Covid-related death into CPNS. The user guide highlights the importance of this reporting being “accurate and timely”.

“Ultimately, the information you provide supports vital public health messaging regarding the containment of the virus,” the guide says, adding that the statistics are used to “inform short- and long-term policy and important guidance”.

These CPNS death records are then validated by regional and national Incident Coordination Centres before they appear in the official daily deaths data published by NHS England showing deaths in hospitals.

Many of the organisations HuffPost UK spoke to about the delayed death cases in the data believed referrals to coroners or inquest proceedings could account for the time lags.

Human rights lawyer Elkan Abrahamson, of Broudie Jackson Canter, who is acting for bereaved families seeking a public inquiry into the pandemic, said: “I suppose the question is, is [Covid-19] on a death certificate and, if it isn’t, it may be that a hospital wasn’t sure if Covid was factor and took some time to investigate that before deciding to register it.”

It is possible to check whether this is the case because deaths registered in NHS England’s daily data fall into two separate categories.

One subset of the data shows deaths following a positive Covid-19 test in the previous 28 days, and another subset shows deaths where Covid-19 is mentioned on the death certificate.

We found 20 cases in the “death certificate” subset between March 2020 and January 2021 where there had been a registration delay of more than three months.

It’s easier to see how there could be delays in this, smaller, section of the data: if, for example, a coroner added Covid-19 to a death certificate following an inquest hearing or further enquiries into the death.

The patient safety charity Action Against Medical Accidents (AvMA) is working with 76 families in relation to Covid-related deaths who are calling for inquest hearings.

These include some cases where the deceased did not have Covid but there was disruption to other non-Covid medical treatment due to the pandemic.

Peter Walsh, the charity’s chief executive, said: “We know that patient safety investigations and complaints investigations are taking much longer to conduct because of the circumstances. 

“If there is going to be an inquest, obviously that might have a bearing [on delays] and I’d imagine there’s a lot of pressure on the parts of the system that register deaths.”

But he admitted: “I’m not not quite sure why there should be as long a delay as the examples you were talking about.”

Even if coroner’s proceedings are a factor, they also cannot account for all of the delays.

HuffPost UK found 44 deaths with a three-month delay, or longer, in the supposedly more straightforward dataset: people who have died within 28 days of testing positive for coronavirus.

These are cases where no death certificate or even cause of death is needed, and the CPNS user guide clearly states they should be reported within 24 hours.

Yet in one case it took eight months and 23 days for a death to show up. Could it really take that long to confirm simply that someone had received a positive test, and subsequently died?

The positive test Covid death cases

All the data in the spreadsheets is anonymous, but we can still tell where each death took place.

The 44 deaths after a positive Covid test with a registration delay of longer than three months were at a number of different hospital trusts across the country.

There were 25 in London, seven in the north east and Yorkshire, five in the north-west, three in the south- east, three in the Midlands, and one in the east of England.

We approached the hospital trusts, who highlighted a number of different reasons for the delays – ranging from missed Covid cases being identified in later audits, to admin or technical errors.

North Cumbria Integrated Care NHS Foundation Trust, which had five cases of deaths with registration delays of longer than three months, said its staff would not enter death data into CPNS until additional information about the patient had been gathered – even if the death itself had been formally confirmed.

The trust said some of this data could only be collected from next of kin and with clinicians working under vastly increased pressure, it had occasionally taken longer to finalise the data.

Other trusts also mentioned difficulties contacting next of kin as being a factor, while some said Covid cases had been picked up during audits and others pointed to system error.

Tameside and Glossop Integrated Care NHS Foundation Trust said it had a case where a death notification was saved in April 2020, but for some reason did not upload to the CPNS system, and the trust was not made aware of this until December, when it was resubmitted.

Reading the CPNS user guide also provides some insight into why delays might occur.

The guide sets how deaths of NHS staff must be reported in CPNS, along with their staff group, role and their last place of work, adding: “This information could feasibly take time to gather, and so may result in a delay in registration.” 

Certain deaths also have to go through an additional admin process to be validated rather than undergoing “auto-validation” within CPNS and so could take longer to process. 

These include deaths where the patient is under 18 or over 109 years of age, where the patient was an NHS worker, if there is no NHS number, where the gap between Covid swab date and date of result is greater than five days, and where the patient died in A&E and the length of stay was greater than one day.

Registration delays 

This issue of registration delays, as the statistical phenomenon is technically known, is not unique to Covid-19 deaths.

Reports by the Office for National Statistics (ONS) on the subject show that some death registration delays can be significant – in 2019, the longest time it took for a death to be registered was nearly 32 years.

The ONS says such cases tend to be where there is no body of the deceased, but where they are presumed dead, or if a body is found after many years. There are also some special cases where deaths are re-registered later because of a retrial or an official inquiry.

But perhaps the most surprising thing we found was this: despite the intense pressure facing the health service, NHS England’s Covid-19 daily deaths data is actually performing extremely well in terms of registration delays compared to other mortality data.

Some 93% of deaths in the NHS England Covid dataset are being recorded within a week of the date of death, compared to 75% of all deaths in 2019.

The last time this level of efficiency was seen within the national mortality statistics was in 2001.

The number of deaths with registration delays of longer than three months in the NHS England data is also very small as a proportion of the total.

The 64 deaths we found represent only 0.09% of the 69,704 hospital deaths in England from March 2020 to January 2021, so have no statically significant impact on the data.

The picture is rather different when you shorten the delay. The CPNS system was designed for deaths to be entered within 24 hours because the data is intended for use in informing decisions and directing public policy.

Yet HuffPost UK found a much more significant number of cases are taking more than 24 hours to be reported. During one week in January 2020, we calculated 47% of deaths with a positive Covid test took more than 48 hours to be recorded.

We asked NHS England and Arden & GEM why these delays are occurring and whether they affected the robustness of the data.

NHS England said: “Hospitals have recorded more than 70,000 Covid deaths over the last year with 93% of these being recorded within a week, and on the rare occasion they are not, NHS regional teams urgently investigate these with the relevant hospital.”

Arden & GEM did not comment, saying: “Your enquiry would be best responded to by NHS England.”

Impact on bereaved families 

None of the grief support charities HuffPost UK contacted about this issue were aware of families who had direct experience of these registration delays in relation to their loved ones’ deaths.

But the charities were handling cases where families had experienced battles to get answers over deaths in which Covid-19 was a factor.

Action Against Medical Accidents has had two Covid-related enquiries from bereaved families in the past week that demonstrate the complexities in some cases.

The charity said one case involves a woman who presented with what were assumed to be Covid symptoms and was told to isolate at home, when in fact she actually had lung cancer that went undiagnosed, and she later died. 

The family is arguing that in a pre-Covid world she would have been assessed properly, and the lung cancer diagnosed and treated sooner. 

In the second case, the hospital thought the deceased had Covid and were treating him as such but the post mortem found no evidence of Covid and determined the cause of death to be inflammation of the heart muscle.

Inquests are due to take place in both these cases but Walsh said, if anything, families often found it difficult to officially raise questions about deaths in the current climate.

“There’s the added guilt, if you like, about people not wanting to cause a problem to a system already under stress,” he said. “So some families would tend to not even ask questions because they know how difficult things are at the moment, whereas in ordinary times they’d be more forthcoming in expressing concerns.”

Linda Magistris, chief executive of The Good Grief Trust, spoke of the wider impacts on families when official proceedings surrounding deaths are subject to delays.

“We know people are having to wait months and months and months, sometimes six or eight months before they even get an inquest, sometimes a year – it really is quite shocking,” she said. “And, of course, the grieving process is really difficult. 

“We had somebody yesterday whose son died 14 months ago and she still hasn’t got the answers she needs. It really is shocking because of the huge volumes [of deaths during the pandemic] – 100,000 people extra.”

Inquest is supporting calls for a public inquiry. Coles said the wider issues in relation to deaths, including the death registration delays, demonstrate the need for it.

“When you look at Covid in the round, I think there is no doubt that there are very important questions to be asked about the government’s handling of this pandemic and a lot of lives lost that could well have been prevented had that been a more effective response very early on. 

“I think every family will say what they want is a proper, effective investigation and scrutiny in the hope that no other family goes through what they’re going through.”

Have you been affected by a death registration delay or are you pursuing an inquest or formal inquiry into a loved one’s death related to Covid-19? If so, contact emma.youle@huffpost.com or DM @emmayoule on Twitter.