A nurse in the UK has been re-arrested on suspicion of murdering eight babies and the attempted murder of another six.

Lucy Letby, who worked at The Countess of Chester Hospital, was quizzed last year over the deaths but was later released on bail.

Cheshire Police have arrested her again, The Sun reports.

Police at the home of Lucy Letby in Chester, the nurse has been re-arrested on suspicion of the murders of eight babies at a hospital neo-natal unit. (PA/AAP)

Her initial arrest came after doctors raised concerns about a "higher than usual number of neonatal deaths" in June 2015.

The nurse was then subsequently questioned by detectives over two days as officers searched her home in Chester.

Detective Inspector Paul Hughes, who is overseeing the investigation, told The Sun : "In July 2018 a healthcare professional was arrested on suspicion of murder in relation to the deaths of eight babies and the attempted murder of six babies at the neonatal unit at The Countess of Chester Hospital.

Lucy Letby, 28, was initially arrested last July on suspicion of the murder of eight babies and the attempted murder of six other infants as part of a police inquiry into the deaths of 17 babies at the Countess of Chester Hospital. (PA/AAP)

"She was subsequently bailed pending further enquiries.

"As part of our ongoing investigation we have today re-arrested the healthcare professional on suspicion of murder in relation to the deaths of eight babies and the attempted murder of six babies.

"She has also been arrested in connection with the attempted murder of three additional babies.

"The woman is currently in custody helping officers with their enquiries."