A hospital nurse murdered a five-day-old baby by injecting air into his stomach through a nose tube, a court has heard.

Lucy Letby allegedly killed the baby boy, child C, just six days after murdering for the first time, when she killed another baby boy, child A, and days later attacked child B, while working at the neo-natal unit at the Countess of Chester Hospital.

Letby, 32, denies seven counts of murder and 10 counts of attempted murder.

Child C died because the air injected into his stomach made him unable to breathe and he suffered a cardiac arrest, Nick Johnson KC, told the jury on the second day of the prosecution opening at Manchester Crown Court.

The boy had been born prematurely at 30 weeks on 10 June 2015 weighing only 800 grams, but despite going into intensive care was in good condition.

Five days later, on the nightshift of 14 June, Letby was supposed to be looking after another, more poorly baby, in another room.

But she was the only person in the room when Child C suddenly and unexpectedly collapsed.

Mr Johnson said an independent pathologist – when reviewing the case – concluded Child C died because his breathing became compromised and he suffered a cardiac arrest.

The prosecutor told jurors: “If you are trying to murder a child in a neo-natal unit, it is a fairly effective way of doing it. It doesn’t really leave much trace.”

He said on the afternoon of 14 June, 2015 – hours after Child C died – the defendant searched on Facebook for the youngster’s parents.

Mr Johnson suggested from the timings that this was “one of the first things she did when waking up” after she had earlier finished her shift at about 8am.

He then moved on to detailing the death of Child D, who the Crown say was murdered by Letby with an intentional injection of air into the bloodstream.

Letby sent “many messages” to friends in the wake of Child D’s death and the preceding deaths and collapses in which she suggested they could all clearly be explained as natural causes.

The defendant later told police she could not explain why she had searched on Facebook for Child D’s parents in the aftermath of her death.

She was also asked about another message in which she had referred to an “element of fate” being involved.

Mr Johnson told the jury: “We say, tragically for (Child D) her bad luck or fate was the fact that Lucy Letby was working in the neo-natal unit that night.”