An immigration official said he "wouldn't necessarily" expect an Immigration Minister to read all the information they are provided before making residency decisions.

This follows Iain Lees-Galloway admitting he didn't read the full file before granting residency to Czech drug smuggler Karel Sroubek.

The Immigration Minister made the decision "within about an hour or so" but he denied he was being sloppy and said he followed the proper process.

Speaking with Mike Hosking, Immigration General Manager Stephan Dunstan said they gave Iain Lees-Galloway all the information he needed to make the decision.

"We do provide a very comprehensive file from a specialist team."

"The file is balanced, in that, it does provide the facts as to why the person is before the Minister and liable for deportation, but it also includes any submission that they have put to the Minister."

However, he said the Minister isn't expected to read all the information provided.

"I would expect him to read the case note then delve in to get clarification on any points they want to."

In the Karel Sroubeck case, Dunstan said Immigration New Zealand didn't make any recommendations about whether he should be deported.

"With these particular cases, we don't provide a recommendation. These cases are just presented on the facts and we provide all the information."

Prime Minister Jacinda Ardern says she is not considering removing Iain Lees-Galloway as Immigration Minister and wouldn't accept his resignation if he offered it.

Speaking with Chris Lynch the Prime Minister said she is focused on fixing the problem, not on Iain Lees-Galloway. 

When asked directly if she would accept Iain Lees-Galloway's resignation she said, "no because at the moment I'm focused on getting this issue resolved".

The Prime Minister also said she is not looking at removing Lees-Galloway's portfolio as Immigration Minister. 

"This is about getting on with fixing the deportation process in a way that they work and this case in partilcaur needs resolution."

However, she said she is "not happy with the decision given that there is contradictory information in the public domain that wasn't contained within the report".

"I've been advised that what Immigration has provided him [Lees-Galloway] around the case, of course, he went through," she said. 

"I'm not saying, however, that I am happy with this process or with this outcome, which is why we have already gone back and have Immigration New Zealand working through the case again."

Jacinda Ardern said she hasn't spoken with Iain Lees-Galloway since yesterday.

Meanwhile, Iain Lees-Galloway is receiving criticism from a Former Immigration Minister who says he "made the wrong decision".

Aussie Malcolm told Kate Hawkesby Lees-Galloway has "got himself a bit removed from reality".

"A Minister of Immigration is called on to make lots and lots of personal decisions about the lives of individuals and, of course, they are hard decisions, some of them are gut-wrenching. But there is a process a good Minister has to go through and part of it is having an instinct for what's acceptable in the public arena."

He said Sroubek's case is "full of red signals" which Lees-Galloway should have taken into account.

"Drug dealer, gang member, in prison, you don't make a quick and easy decision to allow a man like that to stay in New Zealand, not if you're going to keep in touch with the reality of ordinary Kiwi thinking."

Malcolm said the "Immigration Service is very good at putting all the core facts before the Minister".

"In prison - that would have been disclosed. Drug dealer - that would have been disclosed. Criminal - that would have been disclosed. Associate of a nasty gang- that would have been disclosed."

"It's not as if the Immigration Service has gone out of its way to somehow mislead poor old Mr Lees-Galloway. Mr Lees-Galloway has looked at all this information and made the wrong decision."

LISTEN ABOVE AS STEPHEN DUNSTAN SPEAKS WITH MIKE HOSKING