The government has been attacked over loopholes in the Mental Health Act 1983 that allowed a mentally ill man to walk out of a hospital to his death.
Isle of Wight coroner John Matthews said he believed that six fatal incidents involving vulnerable people on the island in recent years could have been avoided if restraint laws were clearer.
He said people were slipping through the net because vulnerable people could only be sectioned if there was a categoric diagnosis of mental illness.
Promising to write to the government to urge it to consider the problem, Matthews said: "Hospitals should be given temporary restraining powers for a short period to give a breathing space."
Matthews' comments came at the inquest into Clifford Cross, of Binstead, Isle of Wight, who was found in the River Medina in August last year, having walked out of St Mary's hospital in Newport.
Cross was admitted to hospital three days before his death, having suffered a fit at his parents' home. A staff nurse asked the duty doctor to have him sectioned, but this was not done because the doctor did not want to wake the consultant.
Recording an open verdict, Matthews said he was concerned there was no crisis management team and only one doctor and a security guard on duty overnight. He said there had been no attempt to start the sectioning process and branded communications between Seven Acres Mental Health Unit and the hospital as inadequate.
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