The mother of twins attacked by Lucy Letby has told the Thirlwall Inquiry she still remembers the night, nine years on, when she caught the neonatal nurse "off guard".

The Thirlwall Inquiry has been hearing evidence this week from families at Liverpool Town Hall into how former neonatal unit nurse Letby was able to commit her crimes at the hospital in 2015 and 2016, and the delays in reporting events to the police.

In August 2015, Letby, 34, assaulted Child E, which caused bleeding, and also injected air into his bloodstream, and nearly 24 hours later she poisoned Child F with insulin.

She went on to murder three babies and attempted to murder five more, until she was removed from the Countess of Chester Hospital’s neonatal unit in July 2016.

A doctor told the parents a post-mortem examination was not necessary for Child E, as it was thought he had died from a bowel condition which was common in premature babies, when in fact no sign of the condition was detected on a X-ray.

And they were informed that Child F’s deterioration was because of a catheter infection, and were unaware he had suffered an episode of hypoglycaemia and that blood tests had shown an abnormally high level of insulin.

Giving evidence on Wednesday at the Thirlwall Inquiry, the mother of Child E and Child F – none of who can be identified – said she could replay in her mind, "like watching a film, bit by bit", the night Child E died.

She said she had gone to the unit with expressed breast milk at 9pm, where she heard Child E "screaming" as she arrived. Letby was nearby, not doing anything, "not making eye contact" and being "abrasive" and "dismissive". Child E was seen with blood around his mouth.

"I think I caught her off guard," the mother told the inquiry. "Something had happened to make [Child E] bleed. Stable babies don't bleed."

Letby told the mother to leave, and said she had contacted the registrar. Records later showed Letby had informed the registrar after 10pm.

Asked what suspicions she had about Letby at the time, or since, she said Letby’s behaviour after the death of Child E was “very different” from other nurses.

She said: “She was very attentive of me. Whenever she used to see me she would hug me.

“She was just as upset as me which, reflecting back on it now, is very odd behaviour, when none of the other nurses were really like that.

“They were very professional and cared for Child F in the correct way, while she was really emotional. I thought she was being kind.

“She looked like every time she spoke to me she was on the verge of tears, very upset.”

The mother of Child E and Child F also said she learned the full details of both incidents at Letby’s criminal trial.

She said: “It took us through our children’s lives essentially hour by hour, and to find out that Child E had that significant bleed to the point of it being very, very unusual, and for no post-mortem to be warranted from that, made me question why.

“Why was the post-mortem not mandatory? Why was it left to me to make that decision?

“I feel guilty for not requesting that, because if that had come back and something would have been on it, there is a lot of babies that could not have been involved in this case and it could have stopped there.

“That weighs very, very heavily on me and that decision was ultimately ours.

“That’s painful to think about so I carry our grief, but the sadness of the other families, because it should never have gone past that point.”

She went on: “And it’s the same when I realised that the insulin reading was there, and it was seen, and nothing was done.

“That could have been an end to this whole horrendously sad turn of events but it wasn’t.

“And I think although the doctors and consultants worked really hard to save Child E, there should have been some curiosity as to why he was bleeding.

“Why Child F’s insulin was not just a little bit over, it was in the 4,000s? Why was it not investigated?

“We put our trust in these people. I put my trust in them to do the right thing and the best thing for my children.”

Inquiry chairwoman Lady Justice Thirlwall told her: “You have absolutely nothing to feel guilty about, nothing. You have nothing to blame yourself for, nothing at all.”

The doctor who advised Child E’s mother that a post-mortem examination would show no new information later apologised to her in the courtroom, as she gave evidence at the criminal trial.

Child E’s mother told the inquiry: “It was a really emotional moment because it was the first time that anyone from the Countess of Chester has apologised for their part in what happened, and I think it was extremely brave to do so.”

She said she first became aware of any investigation in February 2017, when the hospital’s medical director, Ian Harvey, wrote to inform them about an external review of a greater number of deaths than expected on the neonatal unit in 2015 and 2016.

She said: “I received that letter via a black taxi knocking on my door, about 30 minutes before that report was due to go live online on the hospital website.

“I was absolutely mortified.”

Her only previous contact from the hospital, she said, was when they rang twice to ask for the return of a breast pump, which she used at her son’s funeral, when she had in fact already returned it.

The inquiry has heard that families affected were provided with a redacted version of the Royal College of Paediatrics and Child Health report which omitted details about concerns from consultants about 'Nurse L'.

Child E and Child F’s mother told counsel to the inquiry, Rachel Langdale KC, she would have liked to have seen the full report at the time.

She said: “I think the Countess of Chester being transparent and open with what they were investigating would have given me peace of mind, not thinking I had missed something.

“I blamed myself for a lot of things that happened in that time. I don’t think it should have been held back. To do that, I think it’s quite hideous to be honest.”

She subsequently made numerous attempts by phone to set up an appointment with Mr Harvey, but he “hid behind his secretary”.

Asked for recommendations on what could be improved, the mother said that as well as CCTV and supervision of staff welfare, there should be greater enforcement of making sure staff did not take confidential data with them, after the trial heard Letby took notes involving Child E and F home, and later took them with her in a Morrisons carrier bag in a house move.

The mother also suggested that staff's personal mobile phone use is restricted in hospitals.

She explained: "I have been really shocked at the use of mobile phones on the [neonatal] unit through [June 2015-June 2016]. It was not just Lucy Letby, it was other nurses and doctors, knowing they were on shift."

She said staff were "trusted with looking after the most precious things anyone can have", and staff "messaging about nights out or other babies" felt "wrong".

"They are there to look after babies", she said, adding that in emergencies, a nurse could use the unit telephone or bleep a doctor, and that nurses were able to look after babies before mobile phones came along.

Letby, from Hereford, is serving 15 whole-life orders after she was convicted at Manchester Crown Court of murdering seven infants and attempting to murder seven others, with two attempts on one of her victims, between June 2015 and June 2016.

The inquiry is expected to sit until early 2025, with findings published by late autumn of that year.