There are claims of theft, teabag rationing and poor treatment of staff at Woodhaugh Rest Home and Hospital in Dunedin.
Staff and management are at odds, with the Auckland-based general manager suggesting to the Otago Daily Times unhappy staff are resistant to progress and change.
E Tu organiser Ann Galloway said long-serving staff had had their hours cut, while workers on immigration visas appeared to have guaranteed hours.
General manager Janice van Mil denied this claim, saying workers were treated equally regardless of immigration status. The home had about 25 staff, of whom three were on immigration visas, she said.
Ms van Mil said staff hours were cut because occupancy dropped. The home has 39 residents, but has room for 70.
''We don't want to make anyone redundant, so we have had to look at the hours. But we believe that we've been extremely fair.''
Ms van Mil said the home recently improved the choice of food at meal-time, had carried out a ''facelift'' redecoration, and had plans for further changes to improve life for residents.
Some staff felt unsettled by the changes, she said.
Mrs Galloway said cutting work hours was tough on staff and one ''poor woman'' was now ''practically bankrupt''.
''They've cut her hours down so much she can hardly live,'' Mrs Galloway said.
The home was rationing teabags and often ran short of basic supplies, which was embarrassing and difficult for staff, Mrs Galloway said.
Ms van Mil said this was not the case, and the restriction on teabags only occurred because the home switched to a stronger brand.
''We've upgraded our teabags, and you only need to put five in [per pot]. We definitely have the stock on site.''
Ms van Mil said the home was ''losing a lot of stuff'', and installed surveillance cameras a few months ago as a security measure. Losses included a 25kg bag of sugar, a 5kg bag of pasta, and a ''brand new'' dresser and bedside table.
Asked if she suspected staff were stealing, Ms van Mil said: ''I'm not making any suggestion, I'm just saying we have issues with supplies walking out the door.''
Mrs Galloway said the rest-home had been talking about ''theft on a grand scale'' for quite a long time, and the issue never seemed to be ''sorted''.
Ms van Mil said residents were satisfied.
''They are extremely happy with the changes. They are on board, and they are excited going forward.''
The home is owned by the Auckland-based Kiwi Family Group, which was previously called Cressida Healthcare.