The loan disclosure is fuel for critics of the organisation dubbed a ''Ponzi scheme'' by an unnamed health board manager in a paper leaked last year.
Health Benefits Ltd owes the Government $10.2 million from a ''short-term Crown credit facility'' originally requested in mid-2013.
Boards fund HBL's cost-cutting programmes directly, but now details of the top-up loan have emerged.
The Government announced in November it was winding up HBL in the middle of this year.
Reported by Fairfax Media yesterday, the loan is detailed in papers subsequently released to the Otago Daily Times by Finance Minister Bill English's office.
Originally, an $8 million ''temporary credit facility'' was set to expire in April 2014, but the time frame and credit limit were both extended, to $10.2 million, to be repaid at the end of this month.
The money was to create business cases for national programmes for DHB food services, linen and laundry, and a national infrastructure platform.
But the work took longer than expected, and HBL wanted extensions to the time frame and credit limit.
At one stage, it warned the Government it would become insolvent if it did not receive an extension, papers show.
The Crown was ''best placed'' to recover the money from DHBs if that became necessary, officials advised in one paper last year. Ms King said the papers painted a picture of an organisation ''propped up by loans''.
''They just keep rolling it over and they can't pay it.
''And then they need more, and you can see the agitation from [Government] ministers about the fact they need more.''
The money would be repaid out of the budgets of DHBs, which were never properly consulted about HBL's ''empire building'', Ms King said.
She was pleased the Office of the Auditor-general had agreed to investigate the organisation.
Taking the money from health boards was potentially a ''disaster'' for Southern District Health Board (SDHB) because of its financial position, Ms King said.
Association of Salaried Medical Specialists executive director Ian Powell said the loan showed HBL's costs had become out of control.
''It really has been an extraordinary white elephant.
''The Government must have consciously decided to keep this below the radar because it's not a good look.''
HBL spokesman Steve Fisher did not respond to requests for comment.
Health Minister Dr Jonathan Coleman said in an emailed response the loan would be repaid as HBL business cases were implemented in health boards.
He did not respond to a question about whether the SDHB would have to pay any of the loan, given its financial position.
SDHB chairman Joe Butterfield defended HBL, saying it had done a good job of saving money, citing insurance, IT, and banking as examples.
HBL's food service programme with the Compass Group, which the SDHB is considering joining, was also on track to save a significant amount, Mr Butterfield said.
He did not know the detail of the loan, but that health boards might have to pay it back was not surprising, he said.
In November, Dr Coleman said HBL had helped achieve savings of more than $300 million since it was established in 2010.
