The Crown has been forced to buy 12 unsold KiwiBuild homes worth millions of dollars, sparking National's Judith Collins to describe the scheme as "a potential financial black hole for the Government".

A KiwiBuild spokesman said that out of 79 homes completed so far, 12 "have been purchased through the underwrite" and he defended the scheme, saying it was "working as intended".

But Collins said the buybacks were not a good situation because all the homes built under the scheme should sell readily yet the Crown was being lumbered with expense through being forced to buy unsold homes all around