Scale of student visa fraud condemned as 'truly shocking'
An estimated 48,000 immigrants may have fraudulently obtained English language certificates despite being unable to speak English, the government has said.
Immigration Minister James Brokenshire told the Commons that an inquiry into abuse of the student visa system had found evidence of criminal activity, which would now be investigated fully.
Of the 48,000 certificates, 29,000 were invalid and 19,000 were "questionable".
Labour said the scale of the abuse was "truly shocking".
Mr Brokenshire continued: "It is likely that the true totals will be higher."
"The government is not prepared to tolerate this abuse," he said.
"Since the start of February immigration enforcement officers, with the support of the National Crime Agency, together with officials from UK Visas and Immigration, have been conducting a detailed and wide-ranging investigation into actions by organised criminals to falsify English language tests for student visa applicants.
"They've also investigated a number of colleges and universities for their failure to ensure that their students meet the criteria set out in immigration rules."
The probe followed a BBC Panorama investigation earlier this year.
Officers uncovered evidence of "serious concern" at some campuses, and the government has downgraded Glyndwr University in north-east Wales from its status as a "highly-trusted sponsor" of student visas.
In addition, 57 private further education colleges had also had their licences for admitting foreign students suspended, Mr Brokenshire said.
A further two universities - the University of Bedfordshire and University of West London - are no longer allowed to sponsor new students pending further investigations, which will decide whether they too should be suspended.
Immigration enforcement officers had started work to identify migrants who were in the country illegally as a result of the falsified language tests so they could be removed, Mr Brokenshire said.
"The steps I have outlined today shows we will not hesitate to take firm action against those - students, colleges and universities - who do not abide by their legal responsibilities and resolutely pursue organised criminality to bring those responsible to justice," the minister concluded.
But Labour's shadow Home Office minister David Hanson said his statement amounted to an "astounding" admission of "systematic abuse on this government's watch".
"They said, 'No more bogus colleges.' Instead, we now have a major abuse in bogus certificates being issued again," he told MPs.
A representative of Glyndwr University said: "The university is deeply upset that its sponsor licence has been suspended by UK Visas and Immigration and is working with them to investigate the issues raised.
"We have partnerships with a number of suppliers and are incredibly disappointed to have been the subject of any deception or activity that would put that licence under threat.
"To be put in this position by external partners is frustrating as Glyndwr University takes its responsibility as a highly trusted sponsor very seriously and is committed to supporting the continuing education of those genuine international students who demonstrate full compliance with their immigration requirements."
An investigations team would work to have the university's licence reinstated, they added.
Each year, around 100,000 non-EU students get their visas to stay in the UK extended.
The Panorama programme broadcast in February sent non-EU students - who were already in the UK legally - undercover.
They posed as bogus students with poor English, who wanted to remain in the UK to work illegally.