More than 470 UK colleges have been barred in the last six months from accepting new foreign students from outside Europe, the Home Office says.
They either had licences revoked or did not sign up to a new inspection system - part of government efforts to curb abuse of the immigration system.
It estimates the colleges could have brought in 11,000 students.
Immigration Minister Damian Green said the changes to the system were "beginning to bite".
Earlier this year, tighter rules were introduced on student visas, primarily aimed at private colleges offering language or vocational courses.
The changes were designed to weed out those colleges that were in fact involved in systematic attempts to get workers into the UK by helping them pose as students.
The changes aimed to ensure that students could actually speak English, that the courses were credible and that college bosses were meeting immigration and visa obligations.
Some 302 colleges have had licences revoked. A further 172 are being allowed to continue to teach current students - but officials say they cannot sponsor any new ones from outside Europe.
Earlier this year, the UK Border Agency investigated more than 100 colleges after officials recorded a spike in applications from South Asia, shortly before language rules were tightened.
Changes 'begin to bite'
During the investigation, the UKBA found one prospective student, interviewed by phone, could only answer most questions with the word "hello".
Staff at another college tried to avoid an inspection by claiming they were refurbishing the building. Investigators learnt the management were actually hiding inside with the lights turned off. In another instance, a Norfolk college had recorded students as living in Glasgow.
The 11,000 students blocked by the colleges losing licences represent approximately 4% of all student visas granted - but Immigration Minister Damian Green said the changes to the system were "beginning to bite".
He said: "Too many institutions were offering international students an immigration service rather than an education and too many students have come to the UK with the aim of getting work and bringing over family members.
"Only first-class education providers should be given licences to sponsor international students. We have curbed the opportunities to work during study and bring in family members."
Nicola Dandridge, head of Universities UK, said: "It is essential that the government considers the way in which the rules are communicated externally.
"It's important that the UK appears 'open for business' to those individuals who are genuinely committed to coming to the UK to study at one of our highly-regarded universities.
"We must also be conscious of the impact that cutting down on pre-degree courses is having on our universities. Many universities operate pathway programmes with a range of providers."
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