The hunt is on for a hospital killer believed to have been responsible for the three recent deaths, with detectives believing he / she may have poisoned scores of other patients.
The coroner has been asked by the police to check all deaths that occurred in the hospital over the past month, to check if any of them were murdered.  Stepping Hill Hospital in Stockport, Greater Manchester, on average sees four people die every day, which means around 120 deaths will need to be investigated, initially.
However, since it is not known for how long the killer has been on the rampage, officers fear the known cases may just be the tip of the iceberg.
Three deaths and around 36 vials of saline injected with potentially lethal insulin, has officers investigating hundreds others for contamination.
Since, high levels of insulin can give the appearance of natural death, police are unclear as to the extent of the killing.
A large turnover of locum doctors and agency nurses will not make it easy to trace the culprit from amongst hospital staff, if the culprit is one of them.
The hospital killers victims have been identified as two men aged 84 and 71 years, including a woman aged 44 years, while 11 other patients suspected of being poisoned await questioning by the police.
According to sources in the Police, there is no double the intention of the saboteur was to kill.
The Police were contacted Tuesday, after a nurse at the hospital reported a high number of patients with unexplained blood sugar levels.  Testing revealed 36 vials had been injected with insulin.