The Green Party has named in Parliament four medical specialists it says ACC favours because they deliver its targets for getting long-term claimants off the scheme.
It has also released figures that show some specialists have been paid up to $500,000 a year to assess between 300 and 500 claimants - an average of up to $1666 per client.
ACC Minister Judith Collins has responded by saying she will meet the ACC board to discuss ways to ensure the independence of its assessors.
The exchange in Parliament today follows an ACC insider's allegation, reported by TV3 current affairs programme 60 Minutes, that the corporation has been using specialists who provide higher rates of assessments that get clients its books.
Figures released in June show ACC has cut the number of long-term claimants on weekly compensation to 10,773 - a 25 per cent reduction - in the three years from June 2009.
During question time, Green Party ACC spokesman Kevin Hague questioned Ms Collins on four medical specialists he said were favoured by ACC.
He asked whether specialists Martin Robb, Vic du Plessis, Bill Turner and David Beaumont - who were collectively paid $2 million a year by ACC to provide assessments - could be seen as remaining independent of ACC.
Ms Collins responded that she would meet the ACC board to discuss putting in place a system that would achieve "good, robust, and independent medical reports and assessments" that could be seen to be independent by both ACC and its clients.
She noted ACC used 338 doctors to carry out medical assessments and the four doctors discussed on 60 Minutes conducted between 4.7 to 8.7 per cent of those reviews.
Mr Hague later said the huge fees paid to favoured specialists showed they were well and truly wrapped up in meeting ACC's targets to get long-term claimants off the scheme.
"It would be totally unacceptable if the corporation was using doctors it can rely on to deliver assessments that meet that target.
"ACC has a well-established and clear goal of exiting people from the scheme and it is crucial that medical assessments are seen to be truly independent."
Mr Hague said Ms Collins response today showed she seemed determined to actually achieve independent assessments.
The figures show one doctor was paid up to $600,000 a year to see up to 900 clients.