Unscrupulous agents are exploiting the booming overseas student market, promising to fix university and college places in Britain for illegal immigrants with no intention to study.
The British Council has warned universities that bogus overseas students are using fake qualifications and forged documents, often provided by overseas agents or so-called "uncles", in a bid to win visas for study in the UK.
One education consultant warned this week that agents operating in Sri Lanka were openly advertising "study and migrate" packages and "visa guaranteed" services. And in Britain, the Office of the Immigration Services Commissioner has confirmed that it is investigating five cases in which it is alleged that advisers have been "preying on" overseas students already in Britain, promising to arrange visa extensions or permanent immigration.
The British Council is urging universities and colleges to tighten their security systems after discovering an increase in the number of fraudulent applications for student visas from people wanting to come to Britain, usually with no intention to study.
It urges universities to use watermarked paper, to always avoid photocopied or faxed documents when issuing acceptance letters and to always check applicants' claims to have the correct entry qualifications.
The council has updated its advice to institutions for 2002-03 following a THES report in June 2001 that a London-based "agent" had attempted to place 16 Chinese students with fake degree certificates at Derby University.
There are also reports that entry clearance officers in British High Commissions have discovered fake financial documents, purporting to show the "student" has the means to survive in Britain without working illegally.
Neil Kemp, British Council director of education and marketing, said evidence was anecdotal and there were no figures but the council had identified incidences where this might have occurred.
Mr Kemp said: "A large incentive for abuse in poor countries is obviously immigration - economic migration." He stressed that only a small proportion of students "disappear" after gaining entry to Britain on student visas, and that the entry clearance system was generally very good at filtering out bogus students by setting strict entry criteria.
But he said that as numbers increased, abuse became a bigger problem. British universities recruited 141,000 overseas students in 2002 - up 12 per cent on 2001 - who paid £1.5 billion in tuition fees. The total overseas student market could be as big as 1 million students a year.
The Home Office could not provide figures, but it is understood that about 12 per cent of student visa applications are rejected, about twice the rejection rate of other visa applications.
Stephen Airey, an educational consultant who has just completed research into immigration advice for students, recently warned overseas student advisers in UK universities and colleges about unscrupulous agents. He said that some agents, understood to be in Sri Lanka, advertised their services in local newspapers promising "study and migrate" packages, or "visa guaranteed" services. He said he had heard of one case in which two-thirds of a private college's overseas student intake left the college within the first term, some "disappearing".
Linda Allan, deputy commissioner of the OISC, said: "We've been set up to regulate immigration advice because many people seeking it are vulnerable. That includes students, who are not always treated fairly. If any student believes they have been given bad advice, we would urge them to contact our office."
Mr Kemp said that the British Council had discussed a "kitemarking" scheme for overseas agents to weed out unscrupulous operators, but said it would be too expensive and difficult to police. He said it wanted to encourage a self-regulation system.