An individual has been arrested on suspicion of perverting the course of justice in connection with the gross negligence manslaughter investigation at the hospital where Lucy Letby murdered babies, Cheshire Police announced today.

The force said on Wednesday that officers had executed a warrant and searched the home of an unnamed person. They refused to reveal their age or sex.

It comes after three senior executives who worked at the Countess of Chester Hospital during the neo-natal nurse's killing spree were quizzed by detectives in June 2025.

They were later bailed pending further enquiries.

A spokesman for Cheshire Constabulary said today: 'Operation Duet is the ongoing investigation into corporate manslaughter and gross negligence manslaughter at the Countess of Chester Hospital.

'An individual was arrested on suspicion of perverting the course of justice. They have subsequently been bailed pending further enquiries.

'The searches at the property have now concluded.'

The arrest forms part of Cheshire Constabulary's ongoing inquiry into corporate manslaughter at the NHS Trust, where Letby murdered seven premature infants and harmed seven more between June 2015 and June 2016.

In March last year Detective Superintendent Paul Hughes confirmed the corporate manslaughter investigation, codenamed Operation Duet, had been widened to include 'the grossly negligent action or inaction of individuals.'

He said 'those identified as suspects had been notified' but refused to confirm any names.

Letby, 35, is serving 15 whole-life orders after being found guilty of murdering seven infants and attempting to murder seven others, with two attempts on one of her victims, at the hospital's neo-natal unit.

She has twice had applications to challenge her convictions rejected by the Court of Appeal.

According to an independent report, leaked to the Mail's Trial+ podcast, babies' lives could have been saved if hospital bosses had acted sooner to remove Letby from working.

The report, commissioned by the Countess after Letby was first arrested, in July 2018, found managers were 'inexperienced' and missed 14 opportunities to suspend the nurse because they became 'blinkered' to the possibility she was responsible.

Instead of alerting the police, they commissioned a series of ineffectual external investigations, which failed to get to the bottom of why babies were unexpectedly collapsing and dying, the document said.

Executives also 'ostracised' and 'bullied' doctors when they continued to raise concerns and demand police be called in, the report, carried out by independent healthcare consultancy Facere Melius, which has been blocked from publication, concluded.

Although the report does not specifically reveal which babies might have lived, it makes clear that, by February 2016, at least two senior executives at the hospital knew about the link between Letby and the infant deaths.

She tried to kill four children, referred to at her trial as Babies K, L, M and N, and murdered two triplet brothers, Babies O and P, before being removed from frontline nursing in July that year.

'Earlier action potentially would have reduced the number of baby deaths,' the report said.

'Had different decisions been made the spike in baby deaths would have been picked up sooner internally and externally, and potentially, lives could have been saved.'

At the public inquiry investigating Letby's crimes, senior management at the hospital faced serious criticism over their handling of the spike in deaths.

In their closing speeches lawyers for the infants' families accused executives of orchestrating a cover up to protect the reputation of the hospital, lying to the families and bullying the consultants who tried to raise the alarm.

Peter Skelton KC, who represents seven of Letby's victims, said they displayed 'a form of individual and corporate self-protection that should have no place in the NHS.'

Kate Blackwell KC, for the senior executives, said in her closing remarks that they now accepted they should have called in police sooner.

But the barrister insisted it was never expressed to them in 'stark' terms that Letby was causing deliberate harm before June 2016 – when she attacked and murdered Babies O and P and was finally moved from frontline nursing into an administrative role.

Ms Blackwell said managers accepted they had failed to follow safeguarding policies, made mistakes in their communication with the babies' parents and that there was a breakdown in their relationship with the paediatricians, who should have been better supported.

But she insisted all their decisions were taken 'in good faith' and they 'vociferously denied' claims they deliberately and knowingly 'harboured' a murderer or put the hospital's reputation before the safety of babies in their care.

'The senior managers have emphatically refuted the proposition that either their own reputation or that of the Trust was prioritised over safety,' she added.

In law, an individual can be found guilty of gross negligence manslaughter if they negligently breach the duty of care they owe the person who died and it was 'reasonably foreseeable' that such a breach gave rise to a 'serious and obvious risk of death.'

The circumstances of the breach also have to be 'truly exceptionally bad and so reprehensible' that it amounts to gross negligence.

Letby, of Hereford, has always maintained she is innocent and in April 2025 her new defence team submitted evidence from a panel of international experts to the Criminal Cases Review Commission, the organisation that examines miscarriages of justice, in a bid to have her convictions overturned.

The experts claim no murders took place and instead assert that the babies died or collapsed because of natural causes or poor care.

In January 2026 the Crown Prosecution Service announced it would not bring further charges against Letby.

Cheshire Constabulary had submitted files of evidence to consider alleged offences of murder and attempted murder related to two infants who died and seven who survived.

However prosecutors concluded that the evidential test was not met in any of the cases.