Judith Collins has joked Iain Lees-Galloway needs to get better at using Google so he doesn't give residency to any more immigrant criminals.
Mr Lees-Galloway is reviewing his controversial decision to give residency to Karel Sroubek, a Czech man who arrived in New Zealand on a false passport, associated with the Hell's Angels and ended up behind bars for importing MDMA.
He says the decision was based on official advice, without saying what that advice is. Prime Minister Jacinda Ardern said people could "read between the lines", implying Sroubek's life would be in danger should he be deported home.
Since then new information has come to light which contradicts the advice Mr Lees-Galloway says his officials provided. Included in that is evidence Sroubek travelled back to the Czech Republic twice while on bail in 2009 - despite now claiming that would be risking his life.
"If Mr Lees-Galloway knew how to do [Google], he might have made a better decision," Ms Collins told The AM Show on Friday.
Labour MP Michael Wood, interviewed at the same time from Dunedin, wasn't impressed.
"You do a little Google search to make up your policy and make major Government decisions? Okay. We're a little bit more professional than that."
Ms Collins made it clear she was only joking.
"I don't think so. I think people just expect the job to be done."
She criticised Mr Lees-Galloway's explanation that he made the best decision he could on the information provided.
"I've been a minister... and what you have to do is these documents or files will come to the ministerial advisor from Immigration in Iain Lees-Galloway's office, then it would go to his ministerial advisor, then it would go to him after that.
"There would be a lot of discussion... which bit wouldn't you be alerted to? I don't know, application from prison? This guy's been found guilty of kidnapping, multiple drugs, Hell's Angels, ring the wife.
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"Czech Republic is part of the EU - this is not the Democratic Republic of Congo. So what's going on here? Apparently we're supposed to read between the lines."
Mr Wood wouldn't say he would have made the same call as the "very assiduous and hard-working" Mr Lees-Galloway, but only because he hasn't seen the information the Immigration Minister had to rely on.
"Ministers are not gumshoe detectives who go out and look under doormats and try and find this information. They have to rely on good information given to them by officials. That's the case under this Government, and it was the case under Judith's Government, and she knows that very well."
The National Party has called on Mr Lees-Galloway to resign over the affair.
Watch the full panel above.
The AM Show with Duncan Garner, Amanda Gillies and Mark Richardson, weekdays 6-9am on RadioLIVE and streaming live to the rova app on Android and iPhone.