A damning report has concluded that 456 patients had their lives shortened after they were prescribed powerful opioids "without medical justification" at a Hampshire hospital.
Nurses' warnings of an "institutionalised practice of shortening lives" at Gosport War Memorial Hospital went unheeded, according to the report by an independent panel led by former bishop of Liverpool James Jones.
It found that a further 200 patients died as a result of the practice which "had become the norm at the hospital".
There was a "disregard for human life" and hospital authorities, the police, politicians, the Crown Prosecution Service (CPS), and the General Medical Council all failed in ways that would have protected patients, it stated.
Bishop Jones said: "It is not for the panel to ascribed criminal or civil liability.
"It will be for any future judicial process to determine whether culpability and criticism might then be forthcoming.
"But it is clear that this is not the end of the matter, because the panel has called for the health secretary, the home secretary, attorney general and chief constable of Hampshire to act on their investigation."
He praised families who pursued details about the unexpected deaths of their loved ones, saying they showed "remarkable tenacity and fortitude"
Jeremy Hunt made a statement in the Commons, calling the report "truly shocking".
He told MPs the police and the CPS would examine material in the report to consider their next steps and "whether criminal charges should now be brought".
Theresa May called the findings "deeply troubling" and apologised to families over the time it took to get answers from the NHS.
The panel - which has lasted four years at a cost of more than £13m - looked into failings at the hospital between 1988 and 2000.
The panel found that, over a 12-year period as clinical assistant, Dr Jane Barton was "responsible for the practice of prescribing which prevailed on the wards".
In 2010, the General Medical Council ruled that Dr Barton, who has since retired, was guilty of multiple instances of professional misconduct relating to 12 patients who died at the hospital.
The panel said nurses on the ward were not responsible for the practice but did administer the drugs, including via syringe drivers, and failed to challenge prescribing.
Consultants, though not directly involved in treating patients on the ward, "were aware" of how drugs were administered but "did not intervene to stop the practice".
The inquiry did not ascribe criminal or civil liability for the deaths.
However it said relevant public authorities will want to consider whether action now needs to be taken to further investigate what happened at the hospital.
It added: "The secretary of state will want to ensure that families who believe they were affected by events at the hospital have the support they deserve going forward, and also to consider wider lessons."