Immigration officers have given police new information on National MP Kanwaljit Singh Bakshi's alleged involvement in an immigration scam.
A senior Auckland detective has been assigned to the case, which relates to Mr Bakshi allegedly giving false job offers to Indians trying to get into New Zealand.
The investigation began late last year and was closed in March because of insufficient evidence.
Immigration NZ secretly restarted its own inquiries, and a new informant was interviewed last month.
Immigration NZ said last night that after assessing the new information concerning Mr Bakshi "it was decided the case should be referred to the police". This was done on July 20.
The service has also given police a sworn statement that Labour MP Pete Hodgson obtained from another new informant who says complainants were encouraged by people in India to drop the matter.
Mr Hodgson intends to make the statement public in Parliament today.
In the statement the second informant says he was asked to tell the complainants "not to speak against Mr Bakshi because he was going to be the first Sikh MP in New Zealand".
Police last night would not comment on Mr Bakshi's status in the investigation, saying it was too early to determine.
They confirmed the investigation was looking at the role of former Immigration consultant Darshan Singh Bains, who took job offers from Mr Bakshi and gave them to Indians to use as part of their applications to migrate to New Zealand.
"Police are currently assessing that [Immigration NZ] information to determine criminal liability," their statement said.
Mr Bakshi said he knew nothing about the police investigation, and had not had any contact with Immigration NZ since its file was closed.
He also knew nothing of the statement from the new witness.
"I'm not sure of anything so I can't comment," he said.
Mr Bakshi came to Parliament on National's list after unsuccessfully contesting Manukau East.
He has been on leave from Parliament after heart bypass surgery last month, but attended Pakistan independence day celebrations in Auckland at the weekend and is to return to work soon.
The case began before last year's election when a young Indian couple, Kamal Kaur and her husband, Kuldeep Singh, complained to the New Zealand Sikh Society alleging Mr Bakshi made a fake job offer to support Mrs Kaur's 2003 residency application.
The complaint said they paid $25,000 to the immigration consultant, Darshan Singh Bains, and Mrs Kaur got the job offer letter from Mr Bakshi.
The application was denied because she did not meet Immigration requirements and the couple, who never left India, believed the job offer was fake.
But when they were interviewed in India by an Immigration NZ official, they refused to co-operate.
The Immigration NZ report on the investigation - which the Herald obtained under the Official Information Act in May - said the staff member who tried to interview them "formed an impression that [they] may have been paid off by Bakshi or one of his supporters".
The report said there was no evidence to support this impression.
Mr Bakshi told the Herald at the time he did not authorise anybody to act on his behalf but "if you have got any wellwisher who can act on your behalf, I can't say".
Immigration NZ also investigated two other job offers Mr Bakshi made to Indians in conjunction with Darshan Singh Bains in 2003/04.
Mr Bakshi denied receiving any money for the job offers or giving false or misleading information to the Immigration service.
* Bakshi case: The story so far
September: Indian couple complain that then-National Party candidate Kanwaljit Singh Bakshi made them a false job offer as part of immigration scam.
March: Immigration NZ closes investigation. Mr Bakshi says he is cleared.
May: Investigation report obtained by the Herald reveals the case was closed because of insufficient evidence, and an Immigration NZ staffer suspected the complainants may have been paid off.
July: Immigration NZ restarts investigations, refers new information to police.