INZ has 115 Chinese nationals working in its Beijing office and 90 in its Shanghai branch.
Tsoi currently has four cases pending - one of whom has been fighting since 2013 to get visitor visas for relatives from China to visit them in New Zealand.
But INZ area manager Marcelle Foley rejected the claim that people linked with Falun Gong were being denied visas.
"INZ does not ask applicants about their religious or personal beliefs and in any event this has no bearing on whether or not a visa is granted, as long as we are satisfied that the applicant intends a temporary stay for tourism purposes and that they are of good character and meet health requirements," Foley said.
"The onus is on the applicant to satisfy INZ that they meet these requirements."
Foley said the China visitor market was one of New Zealand's largest and most valuable, and about 97 per cent of visa applicants get approved.
Last year 410,130 Chinese visitor applications were processed offshore, mainly in China, and 12,320 were declined.
Over the same period, 25,499 applications were processed in New Zealand and 402 failed to get approved.
"A visitor visa is generally granted for tourism purposes and enables an initial temporary visit for Chinese applicants of up to three months," Foley said.
"(It) enables people to visit New Zealand for a holiday or to visit friends and family."
Flatbush businesswoman and Falun Gong practitioner Jasmine Wang, 40, said none of her relatives have been able to get visas to visit New Zealand — including an uncle, aunt and a cousin.
Her 65-year-old mother, Fang Ling Wang, was granted refugee status in New Zealand because of her close links to the movement.
In the letter declining her uncle's application, INZ said: "We are unable to be satisfied that you have provided sufficient evidence to demonstrate that you are a bona fide applicant who genuinely intends a temporary stay in NZ for a lawful purpose."
Wang believed her uncle had met all requirements for a visitor visa.
"How do you prove intent and being bona fide when INZ already have this preconceived idea that they intend to overstay just because they have relatives who are Falun Gong members," Wang added.