Labour leader David Shearer says he has received assurances from MP Shane Jones that he followed the proper process in an immigration case.
Yan Yong Ming, who is known to politicians as Bill Liu and also goes by the name Yang Liu, is facing charges of passport fraud in the Auckland High Court where details of how he was granted citizenship have come under scrutiny.
In 2008, Mr Jones was Associate Immigration Minister when he overrode official advice and approved citizenship for the Chinese businessman.
On Monday, David Shearer said he had spoken to Mr Jones, who denies receiving money, gifts or travel from Mr Yan.
Mr Shearer says having looked at material Mr Jones has on the case, it appears the process was considered and proper.
The Labour leader said that, while officials had recommended that citizenship not be granted, Mr Jones felt they had not established a clear case against Mr Yan.
In the past few weeks, Mr Shearer has called for ACT Party leader John Banks to be stood down as a minister while police investigate donations to his 2010 Auckland mayoral campaign.
Although the Yan case has called Mr Jones' judgement into question, Mr Shearer says it is different to Mr Banks' case.
He says Mr Jones is not under investigation and will not be stood down from his shadow portfolio roles.
But Prime Minister John Key says Mr Shearer has been hypocritical in the way he has dealt with Mr Jones, saying the Labour leader has simply taken the MP at his word and should have been more cautious about criticising the approach taken with John Banks.
Shane Jones will not comment while the court case is continuing.