The Ministry of Health has changed rest home inspection procedures, following criticism in the wake of the closing of a Palmerston North home yesterday.

After receiving photographs of a 103-year-old resident tied to a bed and complaints about conditions at the Rose A Lea rest home, MidCentral District Health Board (DHB) ordered a spot inspection.

The DHB revoked the license of owners Bryan and Joyce Wenmoth to operate the rest home and moved the 13 residents out.

Rose A Lea had been audited by a ministry contracted team in March.

Ministry's quality and safety manager Rose Hall today told Radio New Zealand it had changed how it conducted inspections.

The operators of Rose A Lea had known when the March audit would take place , she said.

From next year, rest home operators faced unannounced, spot inspections to check for any "slippage" of care , she said.

Even in the March audit, the Rose A Lea home had been found lacking.

At the time of the surveillance audit, there were eight criteria that received a partial attainment rating.

They fell into a range of areas, including "quality and risk management", Ms Hall said.

These included a process for approving restraints.

Others areas of concern highlighted included issues with "medication management" - amid reports of untrained caregivers injecting residents with morphine and insulin - and infection control.

A whistleblower yesterday said the toilets were cleaned only once a week, the home lacked basic facilities for spray-cleaning faeces-stained clothes and bed sheets and the residents were often underfed.

Lobby group Aged Concern said its elder abuse and neglect prevention services were uncovering two cases of abuse of the elderly every day in New Zealand, and suspected this to be the "tip of the iceberg".

"If you're an older person facing abuse or someone who suspects it's happening, you can help stop it," spokeswoman Jayne McKendry said.

"If you see something that's not right, speak up. If you suspect abuse in a rest home, talk to the rest home manager, or Age Concern, your DHB's funding and planning manager, or the Ministry of Health's HealthCert team."

In Parliament today, Labour's aged care spokeswoman Luamanuvao Winnie Laban called for an inquiry into aged care in New Zealand.