A mental health trust says it is planning to install CCTV following the death of a patient in mysterious circumstances.

Maria Morris, 44, was found unresponsive at Bethlem Hospital in south London on 21 September 2021 with four socks down her throat, and a large unexplained bruise on her back.

She died hours later in hospital from a brain injury caused by a lack of oxygen. A consultant who treated her questioned whether she had been assaulted.

An inquest jury at South London Coroners’ court concluded that her death was accidental, but her family says they still have questions about what led to her death.

The inquest heard that Maria Morris, who worked as a teaching assistant, had bi-polar affective disorder.

In September 2021, her family and friends became concerned when she started acting erratically and found that she had stopped taking her medication.

Police were called after she ran away from a friend while walking in a park. When found, she was delusional and taken to Croydon Hospital.

She was transferred to Bethlem Royal Hospital, a mental health hospital run by South London and Maudsley NHS Trust (SLAM), on 18 September where she was sectioned under the Mental Health Act.

The jury was told that while Maria was on the unit, she raised a number of concerns about how staff were treating patients. She told one member of staff that patients were being “punished” at night.

On the evening of the 21 September, Maria was observed by staff in her room at 20:00 and then again at 20:30. At 21:23, a member of staff found her unconscious on the floor of her room, having had a cardiac arrest.

During attempts to resuscitate her, a sock was found in her throat. When paramedics arrived, three further socks were removed from her throat.

By the time she was transferred to Croydon University Hospital, she had suffered a hypoxic brain injury. A few hours later she went into cardiac arrest again and died on 22 September.

The jury was told that Dr Simon Wood, an intensive care doctor at Croydon Hospital who treated Maria, alerted the police to a large bruise on her back.

He also said that, in his view, a patient wouldn’t have been able to push socks down their own throat without gagging. He was concerned that this may have indicated she’d been assaulted.

The jury heard that there was no CCTV used on the wards at Bethlem Hospital and there was nothing in Maria’s notes or observations to explain the bruising.

Maria’s room was locked when she was found. The court heard that most patients had keys for their own rooms, but there was no record on who had what key.

Staff had master keys that could unlock all the patients’ rooms.

In a statement read to the court, Metropolitan police officer DC Herdeep Jugdev said that his investigation had been hindered because Maria’s room in Bethlem had been cleared, and the sock disposed of, before they got there 19 hours after her death was reported.

During their investigation, the police spotted what appeared to be blood under Maria’s nails, although this did not appear to have been tested to see whose it was.

John Taylor, the South London Coroner, told the jury that there was not sufficient evidence to conclude that Maria was assaulted on the ward, or that someone else had pushed socks into her airway.

The inquest heard conflicting evidence from staff at Bethlem about how often Maria was checked on the night she died.

Some documents and witnesses suggested she should have been checked four or five times an hour. Others suggested she should have been checked once an hour.

The jury concluded that Maria had pushed the socks down her own throat, but that her death had been accidental. They were unable to reach a conclusion on whether a lack of observations contributed to her death, because of the conflicting evidence.

In a statement, Maria’s family said she was a much-loved mother, daughter and sister, and that her death “has left a profound and lasting void in the hearts of her family and all who loved her”.

“We are grateful to the jury for having identified that there were missed opportunities around communication, documentation and observations.

“As a family, the idea that more could have been done to keep her safe causes us immense pain.”

The family also said it felt the jury was not allowed to comment on all the issues it considered to be important.

“As a family we still have questions about exactly what happened that night.”

South London and Maudsley NHS Trust (SLAM) says it will be rolling out CCTV in all its wards and opening a new CCTV control centre in November.