The university announced today that it had been suspended from the UK Border Agency's list of Tier 4 Highly Trusted Sponsors while it worked to clarify issues over its handling of students from outside the European Union.
The concerns, which were identified in two recent Border Agency audits, centre on how data on non-EU students are collected and stored, said Malcolm Gillies, vice-chancellor of the university.
Other issues regarding attendance monitoring and English-language testing data also needed to be resolved, he said.
The university will continue to accept applications from international students over the summer, but it will not be able to issue them visas until the suspension is lifted.
International students already enrolled at London Met are not affected, while students granted visas for study in 2012 are also able to take up their places this autumn.
"London Met has worked hard over the last year to rectify previous inadequacies, conducting three of its own audits," Professor Gillies said. "It will instantly rectify any residual deficits in its current practice."
"The university remains a Highly Trusted Sponsor, but its licence is suspended while we resolve remaining issues. In fact, the response to UKBA is being drafted today.
"This is a peak time [for recruitment], and we are keen to make sure the suspension is lifted."
London Met is only the second university known to have been suspended from the Highly Trusted Sponsor register since rules were tightened by the coalition government last year.
Teesside University was suspended from the list in early February after concerns over "administrative processes", but it was reinstated in May.
Professor Gillies said: "London Met and its partners have over 10,000 international students, around 10 per cent of London's total.
"We applaud UKBA's mission to stamp out visa or compliance abuse, and so to support the integrity of British higher education.
"London Met advocates higher education for all those with the qualifications and experience to succeed, whether domestic or international students."