At least 43 women found to be carriers of typhoid fever had been locked away in a British mental hospital, a BBC investigative team learned.
The women were at the Long Grove hospital in Epsom, Surrey, from 1907 until it closed in 1992, the British broadcaster reported.
While they had recovered from the disease, the women, all from the London area, posed a health risk and never were released, records indicated. The majority were admitted between 1944 and 1957.
The Department of Health told the BBC it never had "a policy of incarcerating" anyone in this context.
Most of the hospital's documents were destroyed but histories found two volumes of records.
Jeanie Kennett, a ward manager at Long Grove for 40 years, told the BBC life was a "basic existence" for the patients.
"They're somebody's loved ones, they're somebody's mother, or sister, everybody had forgotten about them -- they were just locked away," she said. "Life was pretty tough; they were seen as objects, it was prison-like -- everything was lock and key."
Hugh Pennington, emeritus professor of bacteriology at Aberdeen University, told the BBC the women would have posed a small risk to the public.