Eventually, he confessed.
His excuse was an immigration advisor told him he did not have to disclose the convictions on the citizenship application because his criminal record was "expunged".
However, Peter Dunne, then the Minister of Internal Affairs, made an order to revoke his citizenship on the advice of his department.
The man - who has interim name suppression - appealed to the High Court on the grounds he was simply following the advice of an immigration consultant.
In rejecting the appeal, Justice Patricia Courtney said there were sufficient grounds for the Minister's decision.
"It is perfectly clear from [suppressed] own statements and from the documents he did deliberately conceal the relevant information.
"No particular level of education or knowledge of the law was needed to answer the straightforward questions about previous convictions."
The fact his criminal record was "expunged" before making his citizenship application was irrelevant, said the High Court judge.
This was because citizenship requires proof of meeting the residency requirements - and the man had definitely failed to disclose his convictions on two visa forms.
Even if the man failed to disclose his convictions on the advice of an immigration consultant, Justice Courtney said his citizenship was "procured by fraud".
"If [suppressed] himself was unaware of the misstatements in the residence application as he claims, residence was still procured through the wilful concealment of relevant information.
"It follows that [suppressed] was not lawfully in New Zealand when he made the citizenship application and therefore could not have satisfied the minimum residency requirements at the time he applied for citizenship."
