Cheshire Constabulary mentioned a search warrant was carried out on Wednesday.
Detectives have arrested a suspect on suspicion of perverting the course of justice in reference to the probe into killer nurse Lucy Letby.
Cheshire Constabulary mentioned a search warrant was carried out at a property on Wednesday, and the person was arrested and later bailed pending additional inquiries.
Letby, 35, from Hereford, is serving 15 whole-life orders after she was convicted at Manchester Crown Court of murdering seven infants and trying to homicide seven others between June 2015 and June 2016.
The infants have been attacked by numerous means whereas Letby labored as a nurse on the neonatal unit on the Countess of Chester Hospital.
In an announcement issued on Thursday, police mentioned: “On Wednesday twenty second April officers from Cheshire Constabulary executed a search warrant at a property in reference to Operation Duet.
“Operation Duet is the continuing investigation into company manslaughter and gross negligence manslaughter on the Countess of Chester Hospital.
“An particular person was arrested on suspicion of perverting the course of justice. They have subsequently been bailed pending additional enquiries.
“The searches on the property have now concluded.
“Both the corporate manslaughter and gross negligence manslaughter elements of the investigation are continuing and there are no set timescales for these.”
