The deaths of two patients at a Stockport hospital are being investigated by police after a batch of contaminated saline was discovered.
Staff at Stepping Hill Hospital alerted police on Tuesday after a nurse noticed several patients on her ward had lower than normal blood sugar levels.
She then found some bottles of saline solution that had been interfered with.
Police said it is not yet clear if the saline had any effect on the 44-year-old woman and 71-year-old man who died.
A spokesman said detectives from the major incident team are working closely with the hospital to establish the full circumstances of the contamination.
Staff and patients who may have been affected and their relatives have been informed.
Det Supt Julian Ross said: "This investigation is at a very early stage and we don't know what effect, if any, the solution has had to the wellbeing of any patients.
"We have recovered a number of ampoules of solution and are working closely with the hospital to try and get to the bottom of what has happened."