Almost six months later, Boochani is understood to still be in NZ awaiting a decision on an asylum application.
NZ law prohibits immigration authorities or government ministers from speaking about asylum bids, or even whether an application exists.
On Monday, Smith suggested Boochani was let into the country only because he had “political friends in New Zealand in the Green party and the Labour Party”.
“I deeply suspect there was interference from further up the ladder or influence because of Boochani’s political connections,” he told Radio NZ.
In response, Prime Minister Jacinda Ardern said the law prevented her commenting on Boochani’s case but the opposition claims were “offensive”.
“I’m not going to act outside of the law but I will call out a statement which I think questions the integrity of our immigration system, which is very robust in New Zealand, and indeed the integrity of parliamentarians,” she said.
Immigration Minister Iain Lees-Galloway kept his response to the corruption allegation short, saying: “He’s wrong.”
The Greens also attacked the suggestion, saying the process was “rightfully independent”.
“Any suggestion otherwise is wrong and baseless,” a spokeswoman said.
A spokeswoman for Smith declined to offer evidence to back up his claims, but the Kaikoura MP stood by them.
Smith pointed to an interview last year when Boochani pledged not to return to Papua New Guinea as evidence that Boochani had falsified his original visa application.
“If [INZ] do their job properly his [asylum] application would fail on the grounds that he filled out a visa incorrectly when he came,” he said.
“On the face of it, he should not have been allowed in.”
Human rights organisations lauded Boochani’s departure from Papua New Guinea back in November.
The 36-year-old conducted a number of speaking engagements, including the sold-out Word Christchurch event that sponsored his trip, in New Zealand prior to the expiry of his visitor visa.
His visit was supported by Amnesty International, which has not responded to requests for comment.
Boochani said last year he had experienced in NZ “exactly the opposite of what I experienced on Manus Island”, where he was incarcerated for four years after attempting to seek asylum in Australia.
“In Manus, I experienced violence, cruelty, humiliation,” he said.
“In New Zealand, I’m welcomed by people. I’ve experienced kindness.
“Many people have stopped in the streets and they show their kindness.”