Prof Gauld has called for an independent review of the formula, which is used to distribute billions of dollars every year.
Contacted this week, he said: ''It's impossible to say whether there is a systematic constraining or starving of the far South through the formula ... and the only thing that would answer that question is a good independent review of it''.
The Government has tried to answer critics by saying the formula is being reviewed, but Prof Gauld says that is an in-house review and not independent.
''The whole thing really needs a good look.''
Prof Gauld was one of the authors of a 2012 report that criticised secrecy around the formula, which prevented researchers from determining the rationale for each area's funding.
Information Prof Gauld was able to extract from the Ministry of Health revealed some stark disparities - South Canterbury's funding adjustment for older people was four times more than Southern's in 2010.
The ODT is seeking internal reports prepared for the funding review, briefings provided to Health Minister Dr Jonathan Coleman on population-based funding and up-to-date figures showing what areas receive for rurality and other special features.
