Police have identified 24 suspects in their investigation into the deaths of hundreds of patients at Gosport War Memorial hospital, one of the biggest care scandals in NHS history. Detectives said 21 people were suspected of gross negligence manslaughter and three others of breaking the Health and Safety at Work Act. Police have begun sending case files to the Crown Prosecution Service (CPS), which will decide whether the suspects are to be charged and with what offences. A 2018 report into events at the community hospital in Hampshire between 1987 and 2001 found that “there was a disregard for human life and a culture of shortening lives of a large number of patients” by giving them painkillers. “There was an institutionalised regime of prescribing and administering ‘dangerous doses’ of a hazardous combination of medication not clinically indicated or justified,” it said. The practice of administering large doses of opioids to patients led to at least 450 of them – and “probably” 200 more – dying sooner than they would have otherwise, the report said. The police investigation, which is being conducted by the Kent and Essex forces’ joint serious crime directorate, has reviewed the medical records of more than 750 patients and 3m pages of documents, and taken 1,200 witness statements from relatives. It is made up of a team of serving and retired detectives. The investigation, codenamed Operation Magenta, had previously identified 19 suspects. Neil Jerome, deputy chief constable of Kent, said the inquiry was “one of the largest and most complex of its nature in the history of UK policing”. “We have now reached the stage where we have started to submit case files to the Crown Prosecution Service,” he said. Police are interviewing suspects under caution and no one has been arrested so far. Relatives criticised previous police investigations into the scandal as ineffective, saying they left them without justice or closure. The hospital was “a death factory”, some relatives have claimed. Rachel Power, the chief executive of the Patients Association, said the identification of the 24 suspects “marks a crucial milestone in this deeply tragic case. While we recognise the investigation’s complexity, we strongly urge the police to proceed with utmost diligence and urgency. The families have endured an unacceptably long wait and deserve swift, comprehensive answers.” Emma Jones, a partner in Leigh Day solicitors who represents several of the families, said: “They have already waited many years for answers into the deaths of their loved ones and progress in this investigation does not appear to have been fast.” Last year the high court ordered fresh inquests into the deaths of three patients: Gladys Richards, Arthur Cunningham and Robert Wilson. Families have been campaigning for years for a Hillsborough-style public inquiry into the scandal. The 2018 report found that relatives who complained about the use of opioids were “consistently let down by those in authority” and that NHS bodies, regulators, politicians, coroners and the CPS “all failed to act in ways that would have better protected patients and relatives”.