Up to 50,000 migrants may have exploited flaws in a new student visa system in its first year to come and work in the UK, a report by Whitehall's spending watchdog says

Under a system introduced in 2009, each student must be sponsored by a licensed college and cannot change institution without gaining permission.

But "key controls" had not been put in place, the National Audit Office found.

http://www.bbc.co.uk/news/uk-politics-17514732