There were calls for tighter controls of colleges
There could be tens of thousands of bogus students in the UK, who entered before the tightening of student visa regulations, MPs have been told.
College leaders told the home affairs select committee they had been warning about bogus colleges for a decade.
The lack of control over colleges had been a "national scandal," said Tony Millns, head of language teaching association English UK.
Immigration Minister Phil Woolas said such loopholes had now been closed.
The committee of MPs heard evidence on bogus colleges - which are often institutions set up as a cover for immigration fraud.
Chip shop college
Mr Millns said it remained a problem that there was so little control over the setting up of colleges.
At present they could be set up by a "couple of people above a chip shop," he said.
Nick Lewis, representing the Association of Colleges, said the term "college" should be legally protected in the way that "university" is protected.
The committee's inquiry followed particular concerns that the misuse of student visas could be an entry route used by terrorists.
But Mr Woolas said that much of the problem of bogus students was in the "past tense" - following much tighter regulations for both colleges and overseas students.
"We have been up-front that this has been a problem. Anyone who is being honest will know that there have been dodgy colleges," he said.
And he played down fears over terrorists entering the country through bogus colleges, saying that anyone wanting to avoid the attention of the authorities might prefer to try more legitimate routes.
Mr Woolas did not have an estimate for how many bogus students might have entered the UK, but he speculated that there could have been more than 2,000 bogus colleges operating before the visa clampdown.
There is now a more tightly regulated register of institutions which can recruit overseas students.
The evidence from Mr Woolas and his officials set out a more active regulation system, including unannounced inspections.
These visits had been carried out on about 10% of institutions which are allowed to sponsor overseas students, MPs were told.
And some of these follow-up visits uncovered fraud - such as the computer equipment and facilities on show for the initial inspection having disappeared when inspectors returned unannounced.