The Government has released a report into the exploitation of migrant workers - especially those from the Philippines - involved in the Canterbury rebuild.
The Ministry of Business, Employment and Innovation research said it was difficult to quantify the extent of exploitative practices but said many people spoken to reported poor working and living conditions for overseas workers.
Construction work in Christchurch. Photo: RNZ / Alexander Robertson
The research said the workers most likely to be exploited in the region's rebuild were those who did not speak English well, came from countries where employment standards were not high, and had financial commitments.
Christchurch immigration lawyer Mark Williams said the first 18 months after the 2011 earthquake was the worst time in terms of exploitation.
"We did see quite a few cases of clear exploitation," he said.
"Examples included Filipino workers who had their passports withheld from employers, they had all sorts of illegal deductions taken from their salary and wages that they didn't expect."
The report said Filipino workers appeared the most likely to be exploited for a number of reasons, including the fear of losing their job or visa if they speak out.
It said workers would often pay between $8,000 and $15,000 to a recruitment agent at home in order to secure a job in New Zealand.
Mr Williams said Filipinos were often naive and did not understand the protection that employment laws in this country offered.
"Coming out to a country like New Zealand and being paid the wages they're being paid to work here is just like winning the lottery."
He said their willingness to work and accept working conditions opened them up to exploitation.
The research said small businesses that had tried to expand quickly in the wake of the earthquakes tended to be the ones which did not know how to manage employees.
A board member for the Recruitment and Consulting Services Association, Ian McPherson, agreed.
He said because the demand for work in the rebuild fluctuated, smaller business owners had not always been able to pay their workers.
"I'm talking about a man in a van whose suddenly got 10 or 15 guys on a job bigger than he's had in the past," he said.
He said these employers did not necessarily have "solid employment practices", safety practices or the financial liquidity to weather the gap between a job being completed and being paid.
Mr McPherson, who owns Enterprise Recruitment, said some Filipino workers were encountering problems outside of their employment, with landlords or their recruiters in the Philippines.
The research said many people spoken to reported overcrowding and high rents in the accommodation workers lived in.
Council of Trade Unions' earthquake recovery spokesman Paul Watson said employers ran head-first into an attractive economic environment, without putting the necessary practices in place to ensure workers were not mistreated.
Mr Watson said he had no doubt that many workers continued to be exploited in the city.
"They tend to keep their heads down a bit and take what's being dished out, which is totally unacceptable."
The Ministry of Business, Innovation and Employment said several initiatives have been - or will be - put in place to reduce the likelihood of workers being exploited.
They included information guides for new migrant construction workers, strengthening the enforcement of employment standards and prosecuting those who break the law.