The deaths of three hospital patients are under investigation after a discovery of contaminated saline solution, Greater Manchester Police said on Friday. Detectives are treating as suspicious the deaths of a 44-year-old woman and two men, aged 71 and 84, at Stepping Hill Hospital in Stockport. Staff at the hospital alerted police on Tuesday after finding vials of solution had been tampered after several patients suffered low blood sugar levels. A further 11 people are believed to have been affected by the incident but they have not been seriously harmed. All of those affected and their families have been informed. Assistant Chief Constable Terry Sweeney said: \"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. \"Understandably there is considerable concern within the hospital and the wider community about this.\" He said all deaths at the hospital meeting relevant criteria would be referred to the coroner and stressed that the investigation was still in its early stages. \"It is important that people are clear in their minds that, as things stand, we do not know for sure if the contaminated saline contributed to the deaths of these three people,\" he added. \"It is a possibility we are looking at alongside the coroner, but we must stress that it will be extremely difficult to establish a link. \"That said we have someone deliberately contaminating saline in the one place that people should feel they are being most cared for.\" He said police were advising the hospital on increased security measures but urged the community not to be \"unduly alarmed\". Chris Burke, chief executive of Stockport NHS Foundation Trust, moved to reassure patients and said the trust was working with police on the investigation. \"It was the staff at the hospital who brought this matter to our attention and I\'ve asked them to continue to be extra vigilant to help safeguard patients,\" he said. \"We have increased security both in terms of access to the hospital and access to medicines and already replaced all saline ampoules across the hospital. \"We are doing all we can to protect our patients and ensure their safety while under our care.\"