Police investigating suspicious deaths at a hospital say they are working flat-out, with 60 detectives on the case.
Ian Hopkins, Assistant Chief Constable of Greater Manchester Police, said the thoughts of officers were with the family of Tracey Arden, 44, George Keep, 84, and Arnold Lancaster, 71, who died at Stepping Hill Hospital in Stockport.
The deaths of all three are being linked to the deliberate contamination of saline solution, with the hospital now at the centre of an intense police investigation.
Insulin was found in a batch of 36 saline ampoules in a storeroom close to ward A1 of the hospital in Stockport, Cheshire.
Detectives believe the insulin was deliberately injected into the saline containers which were used in drips by at least two wards, but they say the three deaths remain unexplained as they await post-mortem examination results.
Mr Hopkins said: "Our thoughts continue to be with the families of Tracey Arden, George Keep and Arnold Lancaster. The anguish they will be feeling at this time must be terrible.
"I would like to reassure them we are doing all we can to find out what caused the death of their loved ones.
"There is an ongoing complex investigation requiring detailed forensic analysis and we are continuing to interview a large number of witnesses.
"We have about 60 experienced detectives working on this. They have worked 24/7 since the investigation began and they working as fast as they can without compromising the quality of the investigation.
"We recognise this is an incredibly difficult time for staff at Stepping Hill Hospital who are dedicated to the care of people and saving life."