The fate of nine Indian students, who have lost their battle to stay in New Zealand after their agents used fraudulent documents to obtain visas, is a disgrace, New Zealand First says.
Party leader Winston Peters says the students are the victims, having been "taken to the cleaners financially and educationally".
He says the fault for corruption in the export education sector lies with Finance Minister Steven Joyce, who was Minister for Tertiary Education, Skills and Employment before the December cabinet reshuffle.
"Mr Joyce pumped up the industry so private enterprise could profit," he said.
"He ignored the need to set up standards and a full-proof system."
Mr Peter called for a full-scale investigation.
"Massive fraud occurred, with crooked agents and officials funnelling thousands of eager students to New Zealand in order to claim commission payments," he said.
Green Party immigration spokeswoman Denise Roche said the government should show compassion and allow the students to stay.
She said National was happy to speed up immigration arrangements for US billionaires like Peter Thiel but now the government was refusing to help those in real need.
Immigration NZ issued a brief statement to say the students hadn't been detained but would be deported if they did not leave the country voluntarily.
"As individuals who have exhausted all options to remain in New Zealand, the students have been invited to make arrangements to depart voluntarily or arrangements will be made for them to be deported," general manager of visa services Steve Stuart said.
"The individuals have not been detained and are not being held in custody."