Police have been called to investigate after a number of saline bags were found to have been "tampered with" at Carlisle hospital.

A member of staff discovered the damage to the bags, at the city's Cumberland Infirmary last week.

Senior clinicians were immediately alerted and Cumbria Police were called on the same day.

A spokeswoman for North Cumbria University Hospitals Trust, which runs the hospital, said it immediately implemented its serious incident procedures.

She added: "We had to wait until today to tell people, because we weren't sure what we were dealing with.

"We have informed the public as soon as we can."

The trust is not aware that any patients have been affected but insisted the situation is being continually monitored.

"There has been considerable work since the incident to review medicines across the hospital and to increase security measures," the spokeswoman added.

Dr Rod Harpin, medical director at the trust, said: “I can confirm the trust contacted the police on Wednesday, January 4 regarding a small number of saline bags at the Cumberland Infirmary in Carlisle which appear to have been tampered with.

"We immediately implemented our serious incident procedures and there is no indication any patients have been adversely affected but we continue to monitor this closely.

"Patient safety is our absolute priority and we will continue to work closely with the police."

A spokesman for Cumbria Constabulary said: “We can confirm that we have been notified by the Cumberland Infirmary in Carlisle of a number of bags of saline solution which have been tampered with.

“The investigation is at an early stage and enquiries are on-going to establish the circumstances and the Constabulary is working closely with the hospital.”

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

If patients have any questions or concerns, they can call the trust on 01228 814247.