The chair of the Accident Compensation Corporation board is disputing a claim that the organisation's funding crisis was manufactured.
ACC plans to cut employee and employers levies from April next year because its finances are in better shape, having managed to reverse deficits and post surpluses of $2.5 billion in recent years.
It was announced on Monday that levies for employees will be cut by 17% and will drop 22% for employers and the self-employed.
Labour says the financial blowout at ACC, as claimed by National when it first took office in 2008, was a crisis created to justify its plans for privatisation.
However ACC board chairman John Judge told Nine to Noon that in the five years before he joined the board, the corporation lost $11 billion.
"The cost of the people who where injured in that period and the people we were looking after who were already injured exceeded the income of ACC."
A lawyer who represents ACC claimants says some have been denied their rights to treatment because the corporation has cut back its services too harshly.
Hazel Armstrong says the corporation needs to get back to providing the service it was set up to provide.