Minister of Land information Louise Upston is defending the independent review of the Overseas Investment Office's good character test.

A report's been released on the OIO after it emerged earlier this year the agency had failed to notify ministers of character problems surrounding two Argentinian businessmen who were granted permission to buy a farming station in north Taranaki in 2014.

The Labour Party is calling the report a whitewash.

Louise Upston said the issue that led to the independent report was based on information that the OIO was aware of.

"I think it's fair to say the process that the Overseas Investment Office have been using for assessing good character is fit for purpose."

Chief executive of Land Information New Zealand, Peter Mersi, the man in charge of the OIO, said the review has confirmed the OIO's systems for checking good character are sound.

But Labour MP David Cunliffe said Mr Mersi is fantasizing.

"If the debacle over the Grozovsy brothers is 'sound and a working system', one would hate to see a system that wasn't working because they've let in people who had criminal prosecutions for toxic waste dumping."

Mr Cunliffe is scathing of the review's quality, dismissing it as a "whitewash", and said it does nothing to improve the country's overseas investment regime.

"It surfaces the fact that the OIO couldn't even do a proper Google search - they told their minister in relation to the Onetai Station case that the Grozovsys were clean, that they had searched and they hadn't found anything - that's contrary to what exactly had happened."