OXLEAS NHS Foundation Trust is facing a lawsuit after a woman killed herself by stuffing tissue in her throat.

The family of Diana Mager is taking civil action against the mental health trust after an inquest into her death at Croydon Coroner’s Court recorded a verdict of misadventure.

Mrs Mager, of Park Road, Beckenham, was a voluntary patient at Green Parks House suffering from psychotic depression, which developed after the birth of her daughter Sofia.

During her stay she was observed by staff, with the level of observation reviewed regularly and varied from time to time.

When she was believed to be responding to treatment at the mental health unit she was allowed periods of unescorted and escorted leave.

During this leave there were several incidents including her smuggling a knife into her room at Green Parks House.

And while on a period of unescorted leave, instead of going to have a pedicure, as she had told staff, she went to the balcony of the Tate Modern members’ room on the fifth floor and climbed over the barrier.

A week after this incident, on August 7 last year, she was being observed at 15-minute intervals.

And she was found unresponsive and unrousable in her room between 11.45pm and midnight after she had blocked her airway with tissue.

Paramedics called to the unit, in the grounds of Princess Royal University Hospital, Farnborough, gave evidence at the inquest saying they had experienced problems dealing with the staff.

Steven Morrison told the court: “I asked for a history of the patient and I did not get any reply from any member of staff in the room.

“I asked again for a history and why the patient was in Green Parks House and I had to ask several times.”

And no Oxleas staff accompanied the London Ambulance Service staff and Mrs Mager on the short journey from the unit to the A&E department at the PRUH on the night she died.

Mr Morrison added: “I asked if someone would accompany us, no one replied.

“Maybe there should be more staff if they weren’t able to supply anyone to come with us.”

During the inquest psychiatrist Dr Markus Bienroth said his team were sorry for the death of Mrs Mager.

But giving evidence Dr Bienroth said even if she had been on level three observation – effectively suicide watch – before her death she still might have died.

And in a statement the trust said: “We note the coroner's verdict of death by misadventure.

“Our own internal investigation concluded that this incident could not have been predicted or prevented.”

Medical negligence solicitor Mark Bowman, of Field Fisher Waterhouse Solicitors, represented Diana Mager’s husband Adam at the inquest.

He said: "My client is deeply saddened by the death of his wife. He has lost a very special person in his life, and his daughter, Sofia, has lost her mother.

“My client has welcomed the opportunity to hear evidence as to how his wife was treated at Green Parks House in the period prior to her death and is now commencing a civil claim in the High Court.”

And the coroner Dr Roy Palmer is considering writing to the trust to highlight issues in care which were revealed during the four-day inquest.