Cheshire Constabulary said the arrests had been made after the investigation was widened to include gross negligence manslaughter in March 2025.

Detective superintendent Paul Hughes, senior investigating officer for Operation Duet, said: ‘As part of our ongoing enquiries, on Monday 30 June three individuals who were part of the senior leadership team at the Countess of Chester Hospital in 2015-2016, were arrested on suspicion of gross negligence manslaughter.

‘All three have subsequently been bailed pending further enquiries.'

Cheshire Constabulary launched an investigation into corporate manslaughter at the Countess of Chester Hospital following the conviction of Lucy Letby in October 2023.

Letby was found guilty of murdering seven children and attempting to murder seven more between June 2015 and June 2016 while working in the hospital's neonatal unit.

Hughes added: ‘Both the corporate manslaughter and gross negligence manslaughter elements of the investigation are continuing and there are no set timescales for these.

‘Our investigation into the deaths and non-fatal collapses of babies at the neo-natal units of both the Countess of Chester Hospital and the Liverpool Women's Hospital between the period of 2012 to 2016 is also ongoing.'

A spokesperson at the Countess of Chester Hospital NHS Foundation Trust said: ‘Due to the Thirlwall Inquiry and the ongoing police investigations, it would not be appropriate to comment further at this time.'