Documents have revealed the Government followed Treasury advice in rejecting a last-minute bid for South Canterbury Finance.
The documents, issued on Friday, show one viable deal was received in the run-up to the company's failure.
South Canterbury estimated the ultimate cost to the Government of accepting the deal would have been $335 million.
Treasury advisor Korda Mentha says that was a best case scenario and would have required special treatment for the buyer.
The Treasury says losses under that scenario could have been as much as $500 million, equal to the estimated cost of receivership.