Immigration officials questioned the decision to grant a wealthy businessman citizenship while he was under investigation by three government agencies, emails reveal.
Labour MP Shane Jones, then a Cabinet minister, awarded citizenship to Yang Liu against the advice of a senior investigator at the Department of Internal Affairs (DIA).
DIA investigator Bruce Ross filed a report recommending that citizenship be declined on the grounds that Mr Liu could not satisfy the "good character" requirement as he was the subject of an Interpol warrant and also under investigation by Immigration New Zealand and the police.
This was because of the discovery that Mr Liu was also known as Yong Min Yang with a different birthdate and had passports under both names.
Mr Jones ignored the recommendation and granted citizenship in August 2008. The decision is now the subject of an Auditor-General's inquiry.
Emails obtained under the Official Information Act reveal a senior Immigration NZ investigator wrote to Mr Ross after learning of the decision.
Russell Ogilvy asked whether Mr Ross recommended that citizenship be declined and whether he had told Mr Jones "to speak with his own department regarding the decision".
Mr Jones was the Acting Internal Affairs Minister in this case but also the Associate Immigration Minister.
"The minister was advised of both the pending police and INZ investigations," responded Mr Ross.
Despite his recommendation, Mr Jones granted citizenship subject to Mr Liu taking the oath of allegiance.
Mr Ogilvy then asked Mr Ross to tell him when the citizenship ceremony would be held.
The emails also reveal that Mr Jones granted Mr Liu an urgent private ceremony at the request of Labour MP Dover Samuels, despite the advice of another DIA official that he did not meet the criteria.
Mr Samuels also wrote three earlier letters lobbying for Mr Liu's citizenship application.
The VIP ceremony was held in a room at Parliament days after Mr Jones' decision in his favour.
The next day he applied for an urgent passport, then changed his name to William Yan.
He stood trial in the High Court at Auckland in May on five charges relating to false declarations on immigration and citizenship papers.
The verdict was not guilty despite Justice Timothy Brewer saying the evidence put before him "proves a situation that is highly suspicious". The judge also said it was "odd" that citizenship had been granted.
The defence said the forms were filled out on Mr Yan's behalf by Shane Te Pou, a Labour Party stalwart, and there had been no intent by Mr Yan to hide his other identity.
Mr Jones has said he granted citizenship on humanitarian grounds because Mr Yan risked execution if he returned to China.
Emails, Aug 7, 2008
Between Immigration NZ investigator Russell Ogilvy and DIA investigator Bruce Ross after being told Shane Jones granted citizenship to Yang Liu.
"Thanks Bruce. Can you please confirm to me that:
1. You had recommended in your report to the Minister of Internal Affairs that Liu should be declined his application for citizenship.
2. You recommended to Mr Jones that he speak to his own department regarding the decision."
"Hello Russell, in answer to your questions:
1. The department recommended that Mr Liu be DECLINED the grant of citizenship.
2. The minister was advised of both the pending police and INZ investigation (of which he is associate minister)."
Yang Liu timeline
May 10, 2005: Yang Liu applies for citizenship. Decision delayed as DIA is not sure of his true identity.
Aug 6, 2008: Shane Jones approves citizenship against DIA advice and despite investigation by Immigration NZ and police. Mr Liu's friend, MP Dover Samuels, was a strong advocate.
Aug 8: Mr Jones approves urgent private citizenship ceremony for Mr Liu after application from Mr Samuels, despite DIA advice that he was ineligible.
Aug 11: Mr Liu becomes citizen in a VIP ceremony at Parliament officiated over by Mr Samuels.
Aug 12: He applies for a passport. Changes name to William Yan.