Elderly patients and dementia sufferers have been "restrained unnecessarily" and given "inappropriate sedation" at a hospital where health watchdog inspectors have declared a major incident.
After the raised "safeguarding concerns" after the inspection this week, a hospital ward has been closed, and patients have been asked to only attend the accident and emergency department if they have a "serious or life-threatening condition".
The health service watchdog found staff struggling to cope with "unprecedented demand" and raised a "small number of safeguarding concerns" with the hospital.
One involved a patient's note detailing that an invasive procedure had been carried when that patient could not give their consent.
The CQC is refusing to give any more details about the safeguarding issues. But the Guardian reports that concerns were also raised about safeguarding issues relating to inappropriate restraint, resuscitation and sedation of elderly people, some with dementia.
The inspectors questioned whether informed consent had been given by some patients in the hospital's emergency assessment unit for some medical procedures, the Guardian reports. The unit closed down admissions in the wake of the inspection.
Prof Mike Richards, the CQC's chief inspector, said: "CQC carried out an unannounced inspection at Colchester hospital this week in response to concerns. The inspection looked at the accident and emergency department and the emergency assessment unit (EAU).
"Following the inspection, we gave feedback to the trust about our safeguarding concerns so that it could take appropriate action to ensure the safety and wellbeing of its patients. We will return to carry out further inspections at the trust and we are working urgently with Monitor to resolve these issues. A full report of CQC's findings will be published on our website in due course."
A spokesman for Colchester Hospital repeatedly refused to confirm or deny the specific allegations in the Guardian relating to the use of restraint and sedation and regarding "do not resuscitate" notices.
The hospital's interim chief executive Dr Lucy Moore said the focus was on "discharging patients".
She told the BBC: "By declaring a major incident and running a sort of command and control process, we ask all our staff to prioritise that."
Dr Moore added that by "diverting resources away from things that can wait" staff could "treat as a priority the discharge of patients".
This is the latest crisis to hit the hospital, which was put in special measures by the health regulator Monitor last November after data inaccuracies in cancer treatment targets meant it breached its licence to provide health services. The CQC found staff were being bullied to alter figures. A police investigation was launched into the data issues. In July the hospital was given an overall rating of "requires improvement".
Liberal Democrat MP for Colchester Sir Bob Russell told the BBC: "We've had a year to 18 months of problems at Colchester General Hospital… but clearly this is very worrying. We may not have even reached the corner yet, let along turning it."