Inspectors have suspended 140 colleges and shut down 15 in the past six months under new immigration rules, the Government said today.
Since last March, all education institutions which want to bring non-EU students into the country need to be approved by the UK Border Agency and granted a "tier four" licence.
Security minister Lord West of Spithead said a previous list held by the former Department for Innovation, Universities and Skills had a record of 4,000 colleges that regularly had foreign students but the official list now stood at 2,000.
Lord West told peers at question time: "In the last six months we have carried out around 600 inspections, suspending 140 and revoking 15 tier four licences."
But Tory Lord Naseby demanded: "Why is it still so easy for these bogus colleges to operate and bring in illegal immigrants?"
Lord West replied: "I don't accept that we have not got a handle on these various colleges."
He added: "We have a team that go and inspect them. They look at whole areas of the quality of the courses they are doing, we make sure they are aware of what they have to do in terms of if students leave that college where they go.
"There have been bogus ones but we are taking enforcement action."
He said a report into the tier four issue ordered by Gordon Brown in November last year would report back "shortly".
UKIP leader Lord Pearson of Rannoch asked: "Is there any truth in the suggestion that of the 66,000 people who came to this country from Pakistan in the nine months to last September, only 29 were interviewed by British immigration officials and the rest by contracted interviewers in Pakistan or elsewhere?"
Lord West replied: "The system is very much that we look at documentation before any of the people come in to give their biometrics and when we have looked at that documentation we assess whether we need to talk to and have a face-to-face interview. We are actually very content that we are achieving good results."