Unions are demanding an inquiry into labour-hire companies following revelations in Australia of exploitation and mistreatment of casual workers.
A highly critical report by Queensland's state government found some workers were hired on sham contracts and not paid holiday or pension entitlements.
In New Zealand, unions say the use of so-called 'arms-length' employment is growing.
They said labour-hire companies had gone from providing genuine temporary jobs, to giving companies the opportunity to exploit workers by abandoning their responsibilities to offer fair, safe and secure work.
E Tū union organiser Shopan Dasgupta said some companies were keeping low-paid workers on insecure contracts, with fewer benefits.
Workers sometimes had to pay their own ACC levies, Mr Dasgupta said.
The union wanted to prove to companies the workers were actually their employees.
"You cannot fob them off as and when you wish," he said.
Cyprian Singh used to work as an agency cleaner at Auckland City and Starship Hospitals.
Despite a glowing work record and promises of a permanent position he was dropped from the roster after 15 months with no reason ever given, Mr Singh said.
He was a hard worker and wanted a fair go for himself and other workers in the same position, he said.
"It wasn't necessarily the money, it's just the security, just to know that you have a job."
Auckland District Health Board did not make anyone available for an interview but said in a statement that Mr Singh had every opportunity to apply for a permanent role, but did not do so.
Mr Singh said he disagreed, but as an agency worker had no come-back.
The majority of the DHB's cleaning staff were now in-house, it said.
However, on any given day up to 55 cleaners are contracted from agencies - approximately a fifth of the cleaning roles.
First Union, which represents 27,000 workers, called on Employment Relations Minister Michael Woodhouse last October to hold an industry-wide audit of labour-hire companies.
Its request was due to complaints from union members about problems similar to those identified in Australia.
Labour Party workplace relations and safety spokesperson Iain Lees-Galloway supported an inquiry in New Zealand.
"That's probably the way forward - get everybody together, talk about the issues, talk about the nature of those employment relations... but eliminate the exploitation as well."
The Recruitment and Consulting Services Association said a New Zealand inquiry was not necessary.
The Queensland inquiry was too wide-reaching and only needed to focus on illegal labour contracting, rather than the industry as a whole, the association said.
Michael Woodhouse declined RNZ's interview request.
A spokesperson said the minister felt it was inappropriate to comment on the unfairness of unwanted long-term casual contracts, because they were not illegal.
Listen to and read a full Insight investigation on this on Sunday morning.
If you are a temporary worker and suspect you are being exploited you can call the Labour Inspectorate at the Ministry of Business Innovation and Employment on 0800 20 90 20.