New Zealand immigration policy approves about 45,000 new migrants annually, and citizenship is not a prerequisite for participation at the polls. Non-citizen permanent residents are granted national voting rights after one year of residency.
"New Zealand is one of only four countries that allows its residents who are not citizens to vote and it is truly a shame that many choose not to exercise their right to vote," Dr Henderson said.
Migrants likely to be "missing" from the electoral roll are those who feel dissatisfied, non-citizens, are single and aged between 24-29 years. Those who are managers, are in the lowest income bracket and employed but not in a full-time paid position are also less likely to be enrolled.
Dr Henderson said those who came under Immigration's family policy were also likely to be non-voters.
Skilled migrants were identified as a group that was most likely to vote.
More than 5000 migrant participants were interviewed between November 1, 2007, and October 31, 2009 for the department's Longitudinal Immigration Survey: New Zealand.
The survey also found a regression with age, with only about 84 per cent of migrants aged 60 up enrolled, down from 92 per cent for those aged between 30 and 39. About 81 per cent of those between 18 and 24 are enrolled.
The Korean Society, which estimates only 2 per cent of local Koreans voted in the 2005 election, believes the number could have again plummeted after seeing a rise in 2008.
"Last election, the community was excited with the introduction of National's first Korean candidate and there were several political forums organised specifically aimed at getting Koreans to vote," said Ted Min, secretary-general for the society.
"But this time there is no real burning issue, so I am not sure if many Koreans had taken part in the election."
Non-voter Eunice Guo, 28, an immigrant from Wuhan, China, said she did not understand the voting system here and did not vote because she did not know any of the candidates standing in her electorate.