Cheshire Police announced Wednesday that Lucy Letby, serving a life sentence for murdering seven babies, has been interviewed regarding the deaths of additional infants.

Letby, 34, was convicted last year of killing seven newborns and attempting to murder seven others between June 2015 and June 2016 at the Countess of Chester Hospital’s neonatal unit, establishing her as Britain’s worst modern serial child killer. A subsequent retrial added an eighth attempted murder conviction.

Following her conviction, police launched investigations into her entire employment history at the Countess of Chester and Liverpool Women’s Hospitals, to determine if more victims existed.

“We can confirm that, following agreement, Lucy Letby has recently been interviewed in prison under caution in relation to the ongoing investigation into baby deaths and non-fatal collapses at the Countess of Chester Hospital and the Liverpool Women’s Hospital,” Cheshire Police stated.

The force indicated that further updates will be provided in due course.

A public inquiry is currently underway to investigate how the killings went undetected and to assess the hospital’s response to doctors’ concerns about Letby before her arrest.

Letby’s case has drawn criticism from some experts regarding the medical and statistical evidence presented by the prosecution, with some media outlets questioning a potential miscarriage of justice.

However, the London Court of Appeal dismissed her appeals against her convictions.