A rail workers' union is taking KiwiRail to court, claiming the state-owned company has breached agreements by outsourcing repairs to Chinese workers.
But the rail company say it's done nothing wrong.
Twenty-seven workers were brought to New Zealand from China to fix asbestos found in 40 locomotives built by China’s state-owned CNR Dalian Locomotive.
The work was done from 2014 as part of the locomotives' warranty and carried out in Hamilton, Lower Hutt and Picton.
A Ministry of Business, Innovation and Enterprise (MBIE) investigation finished last year found the workers' employment conditions were acceptable but it could not verify whether they were being paid New Zealand's minimum wage, following claims they were getting as little as $3 an hour.
The Rail & Maritime Transport Union now says bringing in those workers breached the company's collective agreement and it’s asking the Employment Relations Authority to decide on the matter.
"We're concerned that the decision to bypass KiwiRail workers in favour of CNR workers from China is a breach of our collective agreement," union spokesman Todd Valster said.
"But where workers from China are used, KiwiRail must ensure in its contract with CNR that workers' pay and conditions meet New Zealand standards."
He said the union had made repeated attempts to get Kiwirail to disclose how much the workers were being paid.
But a Kiwirail spokesperson said the company rejected the union's characterisation of the events and had not breached any of its responsibilities.
"However, given the matter is currently before the Employment Relations Authority, it would not be appropriate for KiwiRail to comment further."
The hearing is set down for three days in Wellington.
During MBIE's investigation, both the workers and CNR refused to release wage records but the Chinese company said they were paid allowances for their accommodation, airfares and insurance as well as their normal salary.
Despite not being able to find out how much the workers were paid, the ministry questioned whether New Zealand law would even have applied in the case as the employment contracts were Chinese.
A request by the RMTU to have the case moved straight up to the Employment Court was rejected last October.