The women, all healthcare assistants employed to carry out basic feeding and washing duties, have been suspended by the hospital and barred from working anywhere in the NHS while an urgent investigation is conducted by police and hospital bosses.
Beech Ward, which usually houses about 20 female patients, has been closed as a result of the allegations.
It treats ill and elderly patients suffering from dementia and recovering from operations, strokes and falls.
It is not known how many of the patients have been affected by the alleged abuse. Last night, the daughter of a 91-year-old woman who spent time on the ward earlier this year after a fall described her treatment as ‘cruel’.
Senior managers at the hospital, which is governed by Barts Health NHS Trust, have interviewed 69 patients treated there over an eight-week period between February and April this year to establish the extent of any reported misconduct.
The hospital has refused to disclose further details of the allegations and a spokesman said it had so far not found any evidence of harm to patients.
But the police this week passed a file to the Crown Prosecution Service, which will decide whether formal criminal charges can be brought.