Labour leader David Shearer says he has received assurances from Shane Jones that he followed due process in granting citizenship to Bill Liu, also known as Yong Min Yan, when he was associate immigration minister.
Yan is currently on trial on four counts of fraudulently using documents to gain access to New Zealand and one count of making a false statement.
Last week the court was told that Yan boasted to immigration officials that he had MP friends who would ensure he got citizenship.
Shearer today said he would not stand Jones down from his responsibilities.
After hearing the allegations, which he took seriously, he had spoken to Jones and sought the assurances.
Over the weekend he had talked to other MPs who were aware of the issues involved and he had also reviewed the information Jones had at the time.
"Having looked at the material we have available, it appears that the process which Yong Min Yan (Bill Liu) was granted citizenship was considered and proper."
He said Labour did not have access to departmental files, but was relying on information retained by Jones about the case.
Jones had denied any pecuniary association with Liu.
"He has received no money, gift or travel."
"Shane is not a friend of Mr Liu. He believes he has met him on one or two occasions."
Last week the High Court at Auckland was told that high-ranking officials were stunned when Yan was granted citizenship in 2008 despite being red flagged by Interpol.
This morning, the court was told that an agent paid $5000 to fill out the citizenship application for Yan filled out the forms himself using only information provided by the millionaire's wife.
Shane Te Pou, a Labour party organiser, met businessman Yan in 2005 at a Labour Party fundraiser at Auckland's Viaduct.
Te Pou told the High Court this morning that he took Yan on a trip to the Hawkes Bay to investigate exporting wine to China.
They also met Labour MP Rick Barker on the trip, Te Pou said, though it was "only a catch-up with an old work buddy".
When they returned to Auckland, Te Pou entered an arrangement to fill in Yan's citizenship application.
He told the court he used previous Permanent Resident applications, passports and information from Yan's partner to fill in the form.
In the boxes marked "previous criminal convictions" and "ever been involved in an investigation" Te Pou marked "no".
"It was just an assumption. I didn't ask."
Yan had Interpol flags against his name owing to arrest warrants issued in China.
Te Pou said he did not take a further $5000 completion fee after after he learned Yan had "immigration issues" that were "out of his depth".
This morning Shearer said it was worth noting there were differences in the facts presented in court and those presented by Jones, including that Liu was sworn in a day after receiving citizenship.
Officials had recommended citizenship not be granted, but Jones felt they had not established a clear case against Liu.
He had received a submission from Liu's lawyer John Billington QC, which he had referred to Internal Affairs for comment.
Former Labour MP Dover Samuels had written to Jones requesting a ceremony be held. He had replied to Samuels telling him to talk directly to Internal Affairs.
Citizenship was granted on August 6, 2008 and the ceremony was held on August 11. Jones did not attend.