A SCHIZOPHRENIC with a history of violence escaped from a secure ward in a new £20m North-East mental hospital - to go for a late-night drinking session.

NHS officials confirmed last night that an investigation had been ordered after the 57-year-old man vanished from the Cedar ward at West Park Hospital, in Darlington.

Despite not having a screwdriver or any tools, he managed to open a locked window. Staff believe he may have used his fingernails to pry the locking screws apart.

The patient, who The Northern Echo has chosen not to name, has a history of violence and aggression. He had been detained after being sectioned under the Mental Health Act.

Staff on the ward discovered he was missing at about 10.25pm after a nurse went to check on him. The alarm was raised and a search was carried out in the hospital. His bedroom window was found open.

The police were alerted when the search proved fruitless and photographs of the patient were handed to officers to aid the search.

Bizarrely, the patient then telephoned police to say he had escaped and had gone for a drink.

He was in a busy pub in nearby Cockerton, half a mile from the unit, and was ready to be picked up.

Police returned him to the hospital an hour after they were notified, at 11.48pm.

The incident happened on August 6, but The Northern Echo learned of the security breach only after staff raised concerns.

A worker at the trust, who does not want to be named, said last night: "This is a secure ward. Patients should not be able to escape.

"It is supposed to be a state-of-the-art facility and it only opened recently.

"The ward replaced the Tony White unit, in County Hospital, Durham, and in seven years no one escaped from there. Security was never an issue.

"It is not just about the safety of others but about the patient's own safety."

The ten-bed intensive care unit is a secure centre used to treat people, some of whom have been detained under the Mental Health Act. It houses patients with the most severe mental illness and considered to be at risk of harming themselves or others.

Last night, health chiefs at the hospital, which has been hailed across England as an example of good practice, confirmed the matter had been investigated. As a result, security had been tightened.

An official said it was only a minor breach and declined to say how the patient had beaten security.

Despite the lapse, West Park Hospital, which is in a residential area of Darlington, has won widespread praise from health professionals, patients and staff.

Other health authorities across the country have requested plans for the model and design of West Park, to use as a base for similar units.

A spokeswoman for County Durham and Darlington Priority Services NHS Trust said: "There was an incident which involved a patient being absent without leave from Cedar ward for a short time."

She said: "We have procedures when something like this happens.

"We do carry out a full investigation with any situation like this, and that was done."

The spokeswoman added that the majority of patients posed a risk to themselves, rather than the public, but accepted a minority could pose a danger.