Jonny Humphries
BBC News, Liverpool
Cheshire Constabulary
Lucy Letby is serving 15 life sentences
Prosecutors are considering bringing further charges against Lucy Letby following the deaths and non-fatal collapses of babies at hospitals where she worked.
The Crown Prosecution Service (CPS) received a "full file of evidence" from Cheshire Police regarding incidents at the Countess of Chester Hospital and Liverpool Women's Hospital.
Former neonatal nurse Letby, 35, is serving 15 life sentences for murdering seven babies and attempting to murder seven others, one of whom on two occasions, at the Countess of Chester Hospital between 2015 and 2016.
Cheshire Police has been investigating other incidents going back to 2012, covering Letby's career and training in Liverpool.
The force said it had "submitted a full file of evidence to the CPS for charging advice regarding the ongoing investigation into deaths and non-fatal collapses of babies at the neonatal units of both the Countess of Chester Hospital and the Liverpool Women's Hospital as part of Operation Hummingbird".
The number and exact nature of the potential new offences has not been revealed and it is not known how long it could take for the CPS to decide whether to bring new charges.
In a separate development, the force on Tuesday announced that three former senior managers at the Countess of Chester Hospital had been arrested on suspicion of gross negligence manslaughter.