ACC analysis found that over the time the programme was working there was a reduction in claims even in workplaces where no safety or workplace activity has occurred.
The analysis suggested that even if the training was responsible for half of the reduction in accidents, at best only 16c in every $1 spent did any good, or in other words, 84c in every $1 was being wasted.
The documents reveal that Business NZ and the CTU worked together with ACC to create the venture and doubts about the value of the scheme had existed since at least 2008.
"Business NZ and the CTU have created a nice little earner for themselves", said Mr Williams.
"It's a disgraceful example of big corporate and union welfare chewing through taxpayer cash."
ACC spokeswoman Stephanie Melville today said the corporation decided late last year "that the training programme wouldn't be continued past its current contract".
"While the training programme did provide some value, it did not meet our level of expectations, nor deliver value for money."
CTU Secretary Peter Conway denied the programme was a waste of money, saying workplaces were safer with trained health and safety representatives.
ACC-funded health and safety representative training was "hugely valued by both employees and employers and is a good investment towards confronting our health and safety issues''.
"Independent evaluation of the course undertaken in 2008 was very positive. We know that it delivers value for money - trained representatives are more likely to recognise hazards, and to know what kind of action to take to help mitigate the risks of those hazards,'' he said.
"It is always hard to show that that this kind of preventative course reduces accidents per se, as it is difficult to quantify the value, this will always be an issue. But, a workplace is safer with a trained rep and that is what the CTU and ACC want to ensure.''
Labour's ACC spokesman Iain Lees-Galloway questioned why the corporation was announcing its decision on the programme at the same time as the Taxpayer Union's attack, suggesting ACC Minister Judith Collins may have had a role in co-ordinating the timing of the two statements.
He said the review of the programme appeared to be "politically motivated''.
"Injury prevention programmes have been under attack the whole time National has been in Government. This reflects their short term focus on cost cutting with little interest in the potential for long term savings.
"Effective health and safety training is integral to well-functioning modern workplaces. When corners are cut there can be disastrous consequences, as we saw with Pike River.''
