One advisor expressed concern about this, saying he “should have more courage.” Lucy Letby after having to resuscitate a baby girl.

Dr Ravi Jayaram joined Letby at the Countess of Chester Hospital in February 2016 and stood over the baby, known as Child K, whose breathing tube had been displaced.

The neonatal nurse was later found guilty of attempting to murder Child K.

Dr Jayaram told the Thirlwall Inquiry, which examined the circumstances surrounding Letby’s crimes, that he was outside the nursery in the neonatal unit when he realized she was alone with the baby.

He said he felt “significant discomfort” and decided to go in, even though he thought he was being “irrational and ridiculous”.

“There was a lot of speculation, but I didn’t go in and see anything,” he said.

“When I walked in I saw a clearly deteriorating baby, and when I went to evaluate Baby K the ET (endotracheal tube) had become dislodged.”

Dr Jayaram managed to resuscitate Baby K and said he thought: “How did this happen?”

Asked why he didn’t say anything about the incident at the time, Dr Jayaram told the inquest: “It’s kind of a misdemeanor. Why didn’t I? I lie awake thinking about it.”

“It is the fear of not being believed. This is the fear of being ridiculed. This is the fear of being accused of bullying.

“I had to be braver and have more courage because this wasn’t just an isolated thing. There was already a lot of other information.

“I should have had more courage.”

Dr Jayaram said he first became aware that Letby could “inadvertently and even deliberately harm” babies when he returned from leave following the death of a girl named Child I in October 2015.

He remembered conversations in the corridors with his fellow counselors about Letby’s repeated appearances during sudden and unexplained deaths in the unit.

After the incident with Child K, Dr. Jayaram said fears of intentional harm by Letby had become “a growing elephant in the room”.

He said: “We felt completely powerless to know how to deal with this.”

An external thematic review at around the same time found Letby was on duty at or just before nine in 10 deaths at the unit in 2015, the inquest heard.

Dr Jayaram said: “I naively assumed that the director of nursing and the medical director would look at it, see the pattern and take action.”

He told the inquiry that by the third week of June he felt advisers did not have enough information to raise their suspicions. He conveyed his concerns to Karen Townsendurgent care nursing department manager in a hospital cafe.

He said: “I could have been more frank. “I could have specifically said, ‘You have to remove him from the unit,’ but I didn’t say that.”

Letby went on to kill Child P, a baby boy, before he was finally transferred from the neonatal unit to clerical duties in July 2016 after consultants raised similar concerns with the hospital’s management team.

Hospital bosses subsequently opted for a series of reviews into the rising death rates and did not call in Cheshire Police to investigate until May 2017.

At the beginning of his statement, Dr Jayaram told the hearing: “I want to say to the parents and families of the babies affected by this terrible tragedy that I want to apologize for any personal failings and negligence.”

Letby, 34, from Hereford, is serving 15 life sentences after being found guilty at Manchester Crown Court of murdering seven babies and attempting to murder seven more between June 2015 and June 2016, as well as making two attempts on one of his victims.