London: The spurt in the number of forgeries detected in the student visa applications lodged in New Delhi during 2010 had prompted the British high commission to stop accepting new applications, official sources said here.

A report by the National Audit Office (NAO) said that 6,388 forgeries were detected in the New Delhi office, which was a considerable increase compared to the number of such cases detected in previous years: 2,846 in 2009 and 2,153 in 2008.

In February 2010, the UK Border Agency stopped accepting new Tier 4 (students) applications from North India, Nepal and Bangladesh due to the surge in numbers, while it reviewed existing applications.

The ban was lifted fully in August 2010.

The NAO report said up to 50,000 non-EU migrants may have exploited flaws in the student visa system from 2009 because the Border Agency implemented Tier 4 system before key controls were in place.

"Based on college enrolment rates and changes in application patterns, the NAO estimates that, in its first year of operation, between 40,000 and 50,000 individuals may have entered the UK via Tier 4 to work rather than to study," the report said.

The highest number of forgeries in student visa applications was detected in Islamabad, New Delhi, Dhaka and Chennai, the report states.

The NAO said that the Border Agency had taken little action to prevent and detect students overstaying or working in breach of their visa conditions because the Agency regards them as low priority compared to illegal immigrants and failed asylum seekers.

 "The Agency introduced new controls in 2011 and a fully-documented compliance strategy in December 2011 that are likely to reduce the number of problem students.”

"But it will not be possible to determine the value for money of the Points Based System for students, unless the Agency establishes ways to measure its success in tackling abuse, including how it deals with overstaying, and to establish the full cost of its Tier 4 related activities", it said.

Criticising the David Cameron government, Labour MP Margaret Hodge, who chairs the Commons Public Accounts Committee, said: "This is one of the most shocking reports of poor management leading to abuse that I have seen.

The agency needs to get a grip and fix the way it deals with student visas."

But immigration minister Damian Green said: "This government has introduced radical reforms in order to stamp out abuse and restore order to the uncontrolled student visa system we inherited." Green added: "These include tough new rules on English language, working rights and dependants to ensure only legitimate students come to the UK.

New restrictions on post-study work mean that all but the very best will return home after study." Claiming that the new measures were “beginning to bite”, Green said that the number of student visas issued had dropped considerably in the second half of 2011, compared to the same period in 2010.