More than six months ago, Lucy Letby applied for me to be put on her 'approved visitor' list.

I was sent a form in the post by Sodexo Justice Services which runs HMP Bronzefield where she is held. I dutifully did what was requested of me: filled in all the details, attached a photograph to the form, popped a signed spare in an envelope and returned it all, special delivery.

I know that it arrived safely because it was tracked and I checked. I then waited for the next step in the process – I'm told it usually takes place within weeks – a call from a prison officer who would go through the form and ask me a few questions. Once this was over, I would be 'in the system', and Lucy would then be able to allocate me a visit.

The call never came. My application appeared to have fallen into a black hole. So, I began to make enquiries.

Calls to HMP Bronzefield, where Letby is serving 15 whole life sentences for the murder of seven babies and the attempted murder of seven others, saw me first sent round in circles – and then abandoned on the end of a line I knew was never going to be answered.

I was left with the distinct impression that my application had been quietly placed to one side – which begs the burning questions: who would do that and why?

I made enquiries via legal sources. I asked if it was because I write for a national newspaper? Because, as a former minister, I am a high-profile public figure? I was told no, certainly not. No one had the right to prevent my visit on those grounds.

I can only assume, then, that it is something to do with the fact I have had the audacity to make public on these pages my deep concerns about the safety of the former nurse's convictions.

Lucy Letby is serving 15 whole life sentences for the murder of seven babies and the attempted murder of seven others

Lucy Letby when she was a neonatal nurse at Chester Hospital

I'm not the only one, of course. My Mail colleague Peter Hitchens has written extensively on this subject, as has Sir David Davis MP and, most recently, former health secretary Jeremy Hunt.

Earlier this year, 14 international medical experts who had re-examined all the medical evidence heard at the trial concluded that Letby had not harmed any babies. Their analysis is included in an application currently being reviewed by the Criminal Cases Review Commission (CCRC) made by Lucy's barrister Mark McDonald.

But maybe my visitor application had fallen into the abyss because I've upset too many people in high places with my particular criticism of the chief witness for the prosecution, Dr Dewi Evans.

Dr Evans, 76, is a retired general paediatrician. He is not a qualified neonatologist – a specialist in the care of newborn and premature infants. He last worked in a neonatal unit in 2007.

I have questioned the basis and soundness of his evidence, and his motivation in preparing reports for the Letby trial over seven, no doubt lucrative, years for his business Dewi Evans Paediatric Consulting. Of course, I cannot be sure this is the reason for my application to be languishing in someone's in-tray, but it does make me wonder.

Regular readers will know that, as a former nurse and health minister, I have taken special interest in Lucy's case from the start. And that continues.

Last week, while reading a transcript of a video made by Cheshire Police about Operation Hummingbird – the name of the investigation into the baby deaths at the Countess of Chester Hospital – I came across a comment that really made me sit up.

It was made by one of the senior police officers in the Letby investigation, Det Supt Simon Blackwell, and he was explaining why Cheshire Police had launched their inquiries in the first place. 'You don't often hear of multiple child, baby, infant deaths, they are extremely rare . . . These things are far from routine. They're extreme, even nationally, internationally, very rare,' he said.

I was completely stunned. In my two years as minister responsible for maternity and neonatal care between 2019 to 2021, spikes in, and clusters of, baby deaths took up most of my workload.

I was hauled before a select committee to explain what I was doing about maternity safety and the rising number of baby deaths in places such as the Shrewsbury and Telford Hospital NHS Trust midwifery unit. 

I launched an inquiry into neonatal deaths at East Kent Hospitals and met with parents who were reporting the same concerns regarding Nottingham University Hospitals Trust. The Kirkup Inquiry had recently delivered its verdict on the deaths of 11 babies and one mother at the Morecambe Bay Hospital Trust.

I knew Det Supt Blackwell's claim to be inaccurate. A cluster of deaths is, sadly, not unusual. Why had the police seemed to decide so swiftly that the Chester cluster between June 2015 and June 2016 was the work of a serial killer? I then watched the actual video which had been put out when Lucy was convicted in August 2023 (and later removed owing to reporting restrictions).

The video introduces us to the senior investigation officer, Detective Superintendent Paul Hughes – and what an interesting chap he is. He's the guy on camera whenever new developments in the case are announced. In the video, he states: 'What was clear was that Lucy Letby was the consistent in all this, she was the thread running through them all.'

He was referring to her presence in the neonatal unit at the time of the baby deaths.

Last November, The Mail on Sunday revealed that an audit of mortality data from multiple sources including Freedom of Information requests concluded that Lucy was not on duty when many of the most rapid deteriorations in the health of the babies took place.

Indeed, there was a much broader spike in deaths during the period focused on by the police investigations, bolstering Letby's argument that the fatalities were caused by wider failures of care in the unit. She was not even in the hospital when one of the babies died.

It is also true that, as a single woman, she was called upon more often when she was off duty to shore up staffing levels, sometimes working up to 60 hours per week. This is one reason why so many statisticians question the way the statistical evidence in the case was presented and the claim that she was the 'constant'.

In that same video, another officer makes the point that the police turned to the National Crime Agency (NCA) to appoint expert witnesses. This is where it becomes even more interesting.

Dr Dewi Evans was indeed registered with the NCA as an expert witness. However, in a podcast interview he gave after Lucy's conviction, he states that he first read about the baby deaths in a Sunday newspaper in May 2017.

He told the Letby trial that, in an email to the NCA about an unrelated matter, he mentioned the Chester deaths, writing 'this sounds like my kind of case', which led to Letby's barrister suggesting in court that he was 'touting' for the job.

In the podcast Dr Evans says: 'So I said: 'Look, I'll go up to Chester.' So, I ride there. I met the inspector, Paul Hughes.'

After 'rifling through the [case] notes , a couple of things struck me quickly' – and Dr Evans swiftly decided that there was inflicted injury and a possible killer at large.

At the very least we can say that recollections regarding how Dr Evans was appointed to the case appear to vary.

The CCRC will likely report early next year. Given the enormous doubts swirling around the evidence compiled against Lucy, it is inconceivable to me that the recommendation will be anything other than to refer the case back to the Court of Appeal. The appeal will take until the end of 2026 at least and, if successful, a retrial will be ordered. This whole process could take four years.

Last week, Det Supt Paul Hughes announced the arrest of three senior hospital managers at the Countess of Chester on the suspicion of gross negligence manslaughter. All three were questioned and then released on bail.

They can't be charged until the CCRC has reported or until a retrial is complete. The charges are wholly dependent upon Lucy being guilty. I am suspicious of the timing of this announcement. Could it be an attempt to apply pressure to the CCRC – a counter-blast to the growing clamour of voices demanding Lucy gets a retrial – as it considers the case? A bit like my missing prison visitor's form, it's not a question I can answer.

In the meantime, a young woman, loved and supported by her family, childhood friends and many former colleagues, who has been in jail continuously since 2020, will wait out her 30s in what is possibly the biggest miscarriage of justice this country has ever known. I've asked for another visitor's form to be sent to me. Let's see what happens this time.