Two agents in China are being blamed for a massive student visa fraud.
Random sampling by Immigration New Zealand has found 279 student visas issued at its Beijing branch were fraudulent.
The hunt is now on for 231 of these students believed to be in New Zealand.
Immigration minister Kate Wilkinson says she's been briefed regularly over the last few weeks as the investigation progressed.
"We do a regular audit and that is part of the process to make sure that our systems are robust."
Ms Wilkinson says she's pleased to see the illegal activity detected and acted on quickly.
An operation has begun today to contact and interview all those implicated in the country implicated in the fraud.
Head of Immigration Steve Stuart says each case will be considered on its merits but those implicated are liable to be served deportation orders or notices.
Compliance Operations manager Dean Blakemore says the fraud predominantly involves fake qualifications and falsified bank statements.
He says all are believed to be enrolled with education providers in Auckland.
"We're now in a process of assessing how that happened and trying to locate some of those students that have come down to New Zealand off the back of these applications."
Tertiary Education Minister Steven Joyce says the irregularities were discovered about a month ago.
"What they have done is effectively gone out and done a full sweep, not just in Beijing but in Shanghai and other offices in the area as well, and analysed a whole range of visa applications and ... got it down to these 279 which they know to be fraudulent and the others they've cleared."