Cabinet ministers and long-serving Labour MPs face being dragged into the Taito Phillip Field bribery case because they are potentially key witnesses to the Mangere MP's conduct.
In an unwelcome twist for Labour, ministers Damien O'Connor and Phil Goff could be called to give evidence in court should Mr Field stand trial on bribery-related charges.
A defiant Mr Field yesterday vowed to fight to clear his name after police said they would lay 14 charges against him. They must first go to the High Court to seek approval from a judge to lay the charges, because Mr Field is an MP.
Mr Field said he had done nothing illegal during his 14 years in Parliament. "I have never taken a bribe, I have never taken any money.
"I have never asked, requested or suggested to anybody in any way that they do anything for me in return for my help, any help, or work as a member of Parliament."
He was looking forward to the opportunity to put his side of the story in a judicial setting, and to have the evidence tested "like it's never properly been tested before".
The decision by Detective Superintendent Malcolm Burgess to lay charges against Mr Field follows a nine-month police investigation triggered by a similarly lengthy ministerial inquiry into the MP's dealings by Noel Ingram, QC, last year.
Dr Ingram's inquiry - ordered by Prime Minister Helen Clark - examined allegations that Mr Field gave immigration assistance to Thai overstayers who worked on his properties for little or no pay.
The inquiry cleared Mr Field of having a conflict of interest in his role as a minister but raised questions about his conduct.
Dr Ingram also expressed concern about a lack of co-operation by some witnesses and about some of the answers Mr Field gave him.
Mr Field yesterday claimed Dr Ingram had not necessarily asked the "right questions" of him and could have been more thorough in his investigations.
The Prime Minister yesterday rejected National Party claims that she had failed to deal with unanswered questions about Mr Field after the Ingram report.
Labour has been keen to put distance between itself and Mr Field, and Helen Clark said little yesterday other than that her former colleague was innocent until proven guilty.
But Labour's efforts to ensure it is not associated with Mr Field could be dented if some of its MPs are drawn into a trial.
Mr Goff and MPs Paul Swain and Ross Robertson have been named as having visited Samoa and possibly seeing some of the work done on Mr Field's property at the centre of allegations in the Ingram inquiry.
Mr O'Connor was Associate Immigration Minister at the time, and knows of the representationsMr Field made to him to get work visas for the people he was helping.
The man at the centre of claims against Mr Field, Thai tiler Sunan Siriwan, would relish the opportunity to return from Thailand to give evidence against the MP, lawyer Olinda Woodroffe said yesterday.