A surge in visitor visa fraud cases appears to be the main reason behind a sharp increase in the number of Chinese nationals refused entry into New Zealand, according to Immigration New Zealand.

Figures released under the official information act (OIA) reveal that in the first nine months of the year, 368 Chinese nationals were refused entry to New Zealand at Auckland Airport.

That compares to a total of 222 in 2018 and just 55 in 2017.

Immigration New Zealand (INZ) assistant general manager Peter Devoy said there were a couple of reasons for the sharp increase.

But the primary reason has been an increase in the number of cases of visitor visa application fraud detected when travellers arrive at the border.

This comes after INZ last week issued a warning about unlicensed immigration agents in China.

"INZ is aware that unlicensed advisers are operating in China, as well as in other markets, and it wants to make sure visa applicants from China, who want to travel to New Zealand, are helped and protected," INZ assistant general manager Jeannie Melville said.

"There can be serious consequences for applicants who are misled or cheated by unlicensed or undeclared immigration advisers."

Melville said applications involving "hidden" agents include a false declaration and often contain fraudulent documents – "We will decline those applications".

Devoy said another reason for the sharp increase of Chinese nationals being denied entry to the country is simply because of the rise in the number of Chinese tourists coming to New Zealand.

"In 2014 there were around 243,000 visitor visa arrivals recorded for Chinese passport holders. In 2018 that figure was almost 430,000.

"As arrival numbers rise, some proportionate rise in INZ's enforcement and compliance work is to be expected."

Malcolm Pacific Immigration director David Cooper agrees and said he was not surprised to see this upward trend.

"The rise in these numbers is symptomatic of the rise in the number of people applying [for] visas to come to New Zealand."

He said the Chinese market is in a growth phase.