Immigration Minister Iain Lees-Galloway says he would have "likely" decided to deport Karel Sroubek at the first opportunity if he had known from the outset that Sroubek had returned to the Czech Republic in 2009.
That detail about Sroubek's travel history was emailed from an NZ Customs intelligence analyst to Immigration NZ six years ago - but was subsequently overlooked and not included in the file given to Lees-Galloway to inform his decision about deporting Sroubek.
The email is among hundreds of pages of documents released under the Official Information Act today - the last Friday before Christmas - which also show that immigration officials referred to Sroubek as having the "luck of the charmed".
In September, Lees-Galloway decided to grant Sroubek residency even though he was in jail for drug-smuggling, but he ordered a review of the case and eventually issued a new deportation notice to Sroubek.
Sroubek's return to the Czech Republic was a key part in the Minister's decision to review the case because, if true, it undermined Sroubek's claim that his life would be in danger if he was deported.
This evening Lees-Galloway said that he had "serious concerns" that the information about Sroubek's return to the Czech Republic was not included in the original file.
"If Immigration NZ had been able to present me with evidence that he had returned to the Czech Republic, that would have been very useful."
Asked if he would have decided to deport Sroubek, he replied: "It's likely."
He has expressed his concern to the boss of the Ministry of Business, Innovation and Employment, which includes Immigration NZ, and MBIE's current review of the decision-making process would look at what happened to that information.
Asked if he had been failed by immigration officials, Lees-Galloway said: "I am reserving judgement until that review has been completed."
The email was from a Customs intelligence analyst, whose name is redacted, to Immigration NZ compliance manager Bernard Maritz in March 2012, and said that Sroubek - also known as Jan Antolik - was in the Czech Republic in 2009.
"From Frankfurt he had hired a car and driven to the Czech Republic. The purpose of this trip he claimed (redacted)," the email said.
The Customs analyst had written to Immigration NZ two weeks earlier after reading about Sroubek's case in the media.
"ANTOLIK is a person of interest to NZ Customs and there are a number of reports that may be of mutual benefit to both departments, particularly with his claim that he would be in danger if he was deported to the Czech Republic."
Immigration NZ general manager Stephen Dunstan said the email from Customs was not discovered until the Minister ordered a review of the case.
He said the content of the email referred to a chat between a border official and a travelling companion of a person called Jan Antolik.
"More than one Jan Antolik entered New Zealand at various times. The review (requested by the Minister) of the original case file endeavoured to verify this record of events and was not able to do so," Dunstan said.
"The travel therefore remains unverified and does not show up in the official travel movement history for Mr Sroubek."
Also among the OIA documents was an email from Immigration NZ staff describing Sroubek as having the "luck of the charmed".
Immigration Technical Specialist Janene Smith emailed a colleague following a report in the Herald in 2017 about Sroubek's failed bid to appeal his conviction for drug-smuggling.
"We prosecuted him for using a false identity but Mr Antolik seems to have the luck of the charmed - the Judge discharged him without conviction so that he wouldn't be deported," Smith wrote.
Sroubek was found guilty of using a false identity in 2012, but Judge Roy Wade discharged him without conviction because he believed Sroubek's life would be in danger if he was deported.
Despite the ruling, Sroubek was still liable for deportation, and in 2012 immigration officials started putting together a case to take to the Immigration Minister.
Immigration staff also exchanged messages that appeared to show frustration that Sroubek had not been deported.
When the Herald reported that Sroubek's conviction for using a false identity was discharged, Janene Smith sent an email to colleagues saying: "S'pose you know this John? GRRR!!!!!"
Immigration resolutions team analyst Angela Vinsen replied: "He has been on our radar for a while now."
In early 2013, Immigration NZ wrote to Sroubek to tell him he could be deported - but the case was put on hold as Sroubek faced drug charges.
The documents also included a letter from Sroubek thanking Lees-Galloway for the Minister's initial decision.
"I would like to convey my feelings of gratitude in words to allow me to express my appreciation of the chance that I've been given in your decision to let me legally remain in New Zealand," Sroubek wrote on October 10.
"I can, in all honesty, state that I will gladly comply with all the conditions imposed upon me ... I will not waste the opportunity you've given me to positively contribute to our community and to New Zealand."
The Sroubek case created a political storm over the past two months after it was first revealed that Lees-Galloway had granted him residency in his real name in September.
After initially defending his decision, Lees-Galloway ordered a review after being told that Sroubek's estranged wife may have retracted her earlier support for him, and after court documents showed that Sroubek had been back to the Czech Republic.
After the review, Lees-Galloway issued a new deportation notice to Sroubek on the basis that he should never have been granted a visa to be in New Zealand in the first place, given his prior convictions in the Czech Republic.
Sroubek is appealing the new deportation notice.