A second hospital is now investigating the nurse who police allege is linked to the deaths of at least eight babies.
Lucy Letby was arrested on Tuesday on suspicion of murdering the babies and attempting to kill another six infants. A further three baby deaths were being investigated.
The 28-year-old was a celebrated member of the neonatal unit at the Countess of Chester Hospital where a large number of suspicious deaths of infants occurred.
Letby's arrest stunned colleagues because she is regarded as a "champion for children" she cares for — and helped a massive fundraising campaign to build a new $5 million baby unit at the hospital and has repeatedly spoken about her devotion to her profession since she graduated in 2011.
Letby worked at Liverpool Women's Hospital during her training and health bosses there are now "co-operating with police" as part of their murder investigation.
A spokeswoman said there was "currently" no suggestion any patient had come to harm during Letby's placement.
A conviction for eight murders would make Letby Britain's worst child killer. She is yet to be charged with any offences.
Officers were searching the three-bedroom unit Letby lives in Chester, in northwest England, 2.5km from the Countess of Chester Hospital.
A forensic tent has been set up at the flat, and at the home of her parents.
Letby's neighbours told media they were in disbelief someone so "dedicated to her job" could be accused of anything like what had been suggested.
One told the Chester Chronicle they had known her since she was just 3 years old and "she was lovely, she always has been".
Others said Letby kept to herself and didn't know too many people in the area.
Letby, who has two cats and is registered as living alone at her home, has "liked" UK TV hospital show One Born Every Minute on Facebook.
She is a member of 14 groups relating to helping sick children, including: "Save special care baby units. They need us. One day u might need them."
Several mothers wrote online of their horror that their children were cared for by Letby.
One said her daughter was cared for by her "every day for seven weeks".
Another recognised her instantly as a nurse who was involved in the care of two of her grandchildren.
In an interview with a local newspaper, Letby told why she loved nursing.
"I qualified as a children's nurse from the University of Chester in 2011 and have been working on the unit since graduating," she said.
"I also worked on the unit as a student nurse during my three years of training. My role involves caring for a wide range of babies requiring various levels of support.
"Some are here for a few days, others for many months and I enjoy seeing them progress and supporting their families."
Detectives were called to the hospital when a report revealed an alarmingly high number of deaths at the neonatal unit.
Staff had noticed a "sudden mottling" on the arms, legs and chests of premature or ill babies who unexpectedly deteriorated and had to be revived, and noted similar things happening with babies who died.
Police have been working on the case for over a year.
In the local paper when she graduated in 2011 with Honours in child nursing, her parents said: "We are so proud of you after all your hard work. Love Mum and Dad."
Cheshire Detective Inspector Paul Hughes said: "Since the start of our inquiries and, as the information gathering process has continued, the scope of the investigation has now widened.
"We are now investigating the deaths of 17 babies and 15 non-fatal collapses between the period of March 2015 and July 2016.
"Parents of all the babies are continuing to be kept fully updated and are being supported throughout the process by specially trained officers."