A high-profile police probe into alleged tampering with saline bags at Carlisle’s Cumberland Infirmary has been closed.

The News & Star can today reveal that following a two-year investigation into the allegations no-one will be prosecuted.

The Crown Prosecution Service (CPS) said there was “insufficient evidence” to bring any charges.

Detectives from Cumbria Police arrested a former member of staff - a then 24-year-old woman from Wigton - as part of their investigation.

Senior officers now say she will face no further action.

The saline solution bags in question were found by hospital staff on Wednesday, January 4, 2017.

At the time, the North Cumbria University Hospitals Trust, which runs the hospital, said it immediately implemented its serious incident procedures, alerted senior clinicians and contacted the police.

Saline is commonly used to mix drugs and is routinely administered to patients via a drip.

A police spokesman said: “Cumbria Constabulary can confirm that an investigation into saline bags that were allegedly tampered with at the Cumberland Infirmary in Carlisle has concluded.”

The spokesman added: “The decision was made by the Crown Prosecution Service following a thorough police investigation.

“The trust worked closely with police throughout the investigation.”

A spokeswoman for the CPS said: “The CPS has carefully reviewed evidence gathered by Cumbria Constabulary relating to allegations that saline bags were tampered with at Cumberland Infirmary.

“We have decided that the case failed to meet the evidential test and there is insufficient evidence for a realistic prospect of conviction.”

At the time of the discovery the trust said it was not aware that any patients had been affected.

A spokeswoman for the trust said yesterday: “Cumbria Constabulary has confirmed that no further action will be taken against a former member of our staff relating to an investigation into saline bags that were allegedly tampered with.

“The trust has worked closely with the police throughout the investigation.”

Hospital staff were praised by a senior physician for their quick action in the wake of the discovery. Andrew Goddard, registrar at the Royal College of Physicians, said patients could be reassured - and the fact it had been highlighted, it “showed the system works”.