Older people were put at risk in two substandard nursing homes, according to the regulator for homes in England.
A whistleblower who worked at Laurel Bank Home in Halifax, has told Panorama of the "mental torture" and "abuse" of residents she witnessed.
The Commission for Social Care Inspection (CSCI) says Laurel Bank is now "significantly improved".
But it wants to shut a second home in Halifax, The Haven, which remains open as its owners appeal against closure.
A former care worker at Laurel Bank, who was employed between 2002 and 2003, told Panorama that staff humiliated some residents.
She said relatives were unaware of what was happening: "They only saw what they were supposed to see. People were fed when relatives were there and not when they weren't. They were left to do it on their own."
The forerunner of the CSCI, the National Care Standards Commission, has admitted that it took too long to deal with the problems at Laurel Bank in Halifax.
CSCI inspectors wants to close another home in Halifax, The Haven.
They made 21 visits in one year to intensively monitor standards at the home. Panorama questioned how effective the visits had been in bringing about improvements.
Mike Rourke from the CSCI told Panorama's Vivian White: "We were keeping a very close eye on the establishment but your point is well made that this home did not improve.
"Elderly vulnerable people were at risk."
12 years ago the Law Commission proposed legislation which would protect older people from abuse and neglect but so far, governments have refused to implement it.
Thousands of people contacted Panorama last year after The National Homes Swindle and A Growing Scandal films were transmitted. They shared their experiences about the reality of elderly care provision.
Many voiced concerns about the care of their elderly relatives. They wrote about abuse, a lack of protection and feelings of powerlessness.
Panorama read these emails and made this forthcoming film to address many of the issues brought to the programme's attention.
Please Look After Mum will be transmitted on this site and on BBC One on Monday 12 February at 2030 and then available to watch on the site when you choose.