A health service regulator is investigating claims of abuse at a care home in Lancashire.
Monitor is looking into whether Calderstones Partnership NHS Foundation Trust breached its licence when a patient was abused while in its care.
The health regulator stepped in after a safe guarding case conference identified shortcomings. Police investigated specific allegations of abuse earlier this year but decided to take no further action.
Monitor will now look into whether the episode may be evidence of wider problems at the trust.
The regulator has also written to the Care Quality Commission asking it to undertake an urgent review of standards of care.
No decision has been taken about whether regulatory action is required.