Foreign students may have been unfairly deported from the UK after being falsely accused of cheating in English language tests, a report has warned.
The government withdrew 30,000 visas from non-EU citizens after the BBC uncovered a testing scandal.
The National Audit Office concluded cheating had been “large scale” but innocent people may also been deported.
It said thousands of those accused of cheating had since won the right to remain in the UK.
The Home Office said the NAO’s report highlighted “the scale and organised nature of the abuse”, adding that 25 people had received criminal convictions for their role in the scandal.
In 2014, BBC Panorama broadcast footage showing organised cheating in two English language test centres run by third parties for the non-profit organisation Educational Testing Service (ETS).
The Home Office excluded students and shut down colleges in the wake of the revelations.
The head of the NAO, Sir Amyas Morse, said the Home Office “should have taken an equally vigorous approach to protecting those who did not cheat but who were still caught up in the process, however small a proportion they might be”.
“This did not happen,” he added.
Last month, a woman who came to the UK from Bangladesh in 2010, told the Victoria Derbyshire programme she was at one stage detained for a week after being accused of cheating in the English test.
Fatema Chowdhury, who finished her law degree at the University of London in 2014, denies the allegation and said no evidence of her alleged cheating had been presented to her.
She has not been told to leave the UK, but while remaining in the country cannot work or use the NHS for free.
She said her “dreams and hopes” had disappeared, and she was “desperate” to speak to someone at the Home Office to “prove my innocence”.