Questions are being raised around why not a single case of wage subsidy fraud has been referred for prosecution.

This is despite the Government receiving close to five thousand complaints related to the system being gamed.

Of the complaints - 942 were referred for investigation, with 387 of those so far resolved.

Tax researcher Michael Goussmet told Tim Dower it's unclear what "resolved" means.

"Of those 387 that were resolved, exactly how were they resolved?

"Did those organisations basically say 'we made a genuine mistake and we paid the money back', or what?"

Speaking to the NZ Herald, according to Finance Minister Grant Robertson, this is good news.

Although he wouldn't comment on the fact there have been no prosecutions, he said he considers that half a billion dollars being paid back was "a success".

LISTEN ABOVE