Canterbury Employers' Chamber of Commerce wants to know what has happened to more than 50,000 people no longer covered by the Government's employer support subsidy.
It is to conduct a survey to establish the facts.
The subsidy was introduced after the magnitude 6.3 earthquake on 22 February but only 10% companies are now claiming government assistance.
Chamber chief executive Peter Townsend says it's unclear how many businesses previously using the subsidy have resumed normal trading.
Latest figures show an increase of only 858 unemployment benefit claimants in Canterbury since the February earthquake.
But the data does not include Christchurch, where interviewing has been suspended by Statistics New Zealand.
Earthquake Recovery Minister Gerry Brownlee says fewer people in the region may be on the unemployment benefit because more businesses are managing to stay afloat than originally thought.
Mr Brownlee says businesses have exercised extraordinary innovation to stay afloat.
The Council of Trade Unions says it is not good enough that the Government has no way of tracking better information on workers, but Mr Brownlee says many people may simply be back in work.
He says the subsidy gave businesses the breather they needed to re-work their business plans after the earthquake.