The National Party is surprised New Zealand immigration officials didn't consult their Australian counterparts before granting a visa to refugee author Behrouz Boochani.
Immigration New Zealand said it did not seek information from across the ditch before granting the Kurdish-Iranian author a visa.
Boochani has been in New Zealand since November and he is believed to have applied for asylum.
He was detained in Manus Island for six years under the Australian Government's policy to deter asylum seekers arriving by boat.
There, he wrote a book via WhatsApp on his phone, which won two major literary prizes in Australia.
He was granted a limited visa by Immigration New Zealand (INZ) to attend a book festival in Christchurch.
National Party immigration spokesperson Stuart Smith said Boochani appeared to have been excluded from Australia, making him ineligible to come to New Zealand without a special direction.
He said despite that, the response to a parliamentary written question showed no contact was made with Australian officials before he was granted the visa.
"Which was surprising given the high profile nature of Boochani and the fact that the Australian foreign minister said that Boochani would never set foot in Australia.
"It appears that Boochani has been excluded from entering Australia. Now the law is really clear, immigration rules are clear that anyone who is excluded or been deported from another country, is not allowed to enter New Zealand, the only way they can get in is for a minister to sign it off."
He travelled through the Philippines to get to Auckland so that his flight did not touch down in Australia.
In a media interview, the author said he might seek asylum here.
"When you apply for a visitor visa you must plan to leave before your visa expires," Smith said.
"But Boochani was reported in the ABC the day before he arrived in New Zealand, when he left Port Moresby, saying that he wasn't going back to Papua New Guinea, he might go to the United States where he's been accepted for asylum or he might just stay in New Zealand.
"There are two possibilities: either the minister has actually signed off on Boochani's entry into New Zealand - he was met by Labour and Green MPs and given some sort of a royal welcome almost - so that's one possibility.
"Another possibility is that he's just played the immigration system like a violin and been able to waltz through into New Zealand, filling out an immigration form saying that he intended to leave when he clearly had no intention to - because he stated that publicly before he arrived in New Zealand."
Questions to the government about it went unanswered, he said.
"They just completely won't talk about it at all," he said.
"I think they're very embarrassed about it, which makes me deeply suspicious. What have they got to hide?
"They could make this all go away by coming out and saying 'look, we didn't know about this, it slipped past our normal processes', or they could come out and say, actually, he's been excluded from Australia but we approved him' and give their reasons, whatever they are. They're playing fast and loose with our international reputation."
INZ said in a statement the immigration minister was made aware of Boochani's visitor visa application but as it was an operational decision the minister was not involved in the decision.
"An immigration officer must be satisfied that an applicant for a temporary visa truly intends a temporary stay in New Zealand," a spokesperson said.
"I can confirm that Behrouz Boochani was granted a Limited Visa for the specific purpose of speaking at a conference in Christchurch.
"For legal and privacy reasons, INZ is unable to provide any further comment."
Previously, the government has said it could not confirm or deny whether INZ has received an asylum claim from Boochani, under laws that keep such claims confidential.
Boochani was approached for comment via an intermediary, who said an announcement on Boochani was likely once there was any news that could be legally shared.
In December 2019, he revealed he was still in New Zealand despite his 30-day visa expiring.