A FEMALE "healthcare professional" has been arrested on suspicion of murdering eight babies and attempting to kill six others at a hospital in England.
Cheshire Police said the woman's arrest was a "significant step forward" in an investigation into infant mortality at the Countess of Chester Hospital in Chester.
The investigation involves the deaths of 17 newborns at the hospital's neonatal unit between March 2015 and July 2016, the force added.
Detective Inspector Paul Hughes said the probe also involved 15 "non-fatal collapses".
The arrested woman is currently in custody.
Speaking this morning, DI Hughes, who is leading the investigation, said: "Since the investigation was first launched in May 2017, a dedicated team of detectives have been working tirelessly on this case.
“This is a highly complex and very sensitive investigation and, as you can appreciate, we need to ensure we do everything we possibly can to try to establish in detail what has led to these baby deaths and collapses.
“As a result of our ongoing enquiries we have today (Tuesday, July 3) arrested a healthcare professional in connection with the investigation. She was arrested earlier this morning on suspicion of murder in relation to eight of the babies and attempted murder in relation to 6 of the babies and is currently in custody.
“Whilst this is a significant step forward in our enquiries it is important to remember that the investigation is very much active and ongoing at this stage.
"There are no set timescales for this coming to a conclusion but we remain committed to carrying out a thorough investigation as soon as possible".
He added that families, staff and patients at the hospital were "being kept fully updated" and are being supported throughout the process by specially-trained officers.
"This is an extremely difficult time for all the families and it is important to remember that, at the heart of this, there are a number of bereaved families seeking answers as to what happened to their children."
Medical Director at Countess of Chester, Ian Harvey, said asking police to investigate the baby deaths had not been "something we did lightly, but we need to do everything we can to understand what has happened".
He added the neonatal unit was "safe to continue in its current form" and remained open to women over 32 weeks in their pregnancy.
The Countess of Chester Hospital, which looks after about 400 babies a year, stopped providing care for those born earlier than 32 weeks in July 2016 after it reported "a greater number of baby deaths and collapses than normally expected".
An independent review by the Royal College of Paediatrics and Child Health last year said no "definitive explanation" had been found for the increase in mortality rates at the neonatal unit and there were no "obvious factors" linking the deaths.
Cheshire Police have not yet revealed the specific role of the "healthcare professional" at the hospital.