An investigation into the death of a woman who died after drinking Flash liquid in hospital has not ruled out the possibility she was killed deliberately.

A pre-inquest review hearing at Brighton heard police cannot be sure a third party was not involved in the death of Joan Blaber.

The 85-year-old died at the Royal Sussex County Hospital in the city after the drink by her bed was switched with the floor cleaner.

Family members were present at her bedside when the clear jug she had been drinking from was replaced with a darker one.

CCTV picked up cleaners moving five litre drums of Flash around the hospital although it is not thought to be connected to the death of Mrs Blaber who had been admitted to hospital following a minor stroke.

After being treated for leg ulcers, Mrs Blaber was sent home to Lewes.

She was readmitted to the same hospital following the stroke before her death on September 23 last year.

Flash liquid was removed from the hospital following the death of Mrs Blaber.

It was reintroduced in March this year after complaints wards did not look as clean as they should, the coroner said.

Senior coroner for Brighton Veronica Hamilton-Deeley said: “I’m having a job understanding why you can’t use something else which doesn’t run the risk of being ingested because we still have no idea how this happened and we can’t rule out that this was done deliberately.

“We are still in the midst of uncertainty and yet, the hospital has reintroduced the cleaning fluid for cosmetic reasons.”

The coroner also asked for assurances from the hospital when the full inquest is heard in September that there could be no repeat of Mrs Blaber’s death.

“It has been reintroduced and that worries me,” the coroner said.

The hospital was ordered to improve after an unannounced visit by inspectors from the Care

Quality Commission found the Royal Sussex County Hospital had inadequate safety measures in place.

Inspectors found cleaning fluids still incorrectly stored.

The Sussex police investigation is on hold with no lines of inquiry left to pursue.

Pain medication could also have been a factor in the death of Mrs Blaber, the pre-inquest review heard.

The coroner said pain medication may have contributed to her confusion after being admitted for the minor stroke before drinking the cleaning fluid.

“She might have noticed it was not her usual jug and what

she was drinking had an unusual smell and an usual taste,” the coroner said.

Mrs Blaber was moved late at night from intensive care to the stroke ward where she died 36 hours later.

The full inquest will be heard in front of a jury in Brighton later this year.