Innocent people may have been removed from the UK after they were wrongly accused of cheating in English language tests

Whitehall's spending watchdog examined the Government response to a scandal that led to thousands of visas being cancelled.

It was "reasonable" based on the balance of probabilities to conclude there was cheating on a "large scale", the National Audit Office concluded.

But it said the Home Office's action against overseas students "carried with it the possibility" that some of those affected might have been branded cheats and removed from the UK without being guilty.

The report also revealed that thousands of people accused of cheating have won the right to remain in the country.

Sir Amyas Morse, head of the NAO, said: "When the Home Office acted vigorously to exclude individuals and shut down colleges involved in the English language test cheating scandal, we think they 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."

The NAO said that in 2014, BBC Panorama broadcast footage showing "organised cheating" in two English language test centres run by third parties on behalf of non-profit organisation Educational Testing Service (ETS).

ETS used voice recognition technology to establish who had cheated by having someone else sit their test.

After review by human listeners and other checks, ETS identified 97% of UK tests taken between 2011 and 2014 as suspicious, with 58% of 58,459 tests classified as "invalid" and 39% as "questionable".

The Home Office responded by investigating colleges, test centres and students, and began cancelling the visas of those it considered to have cheated in the Test of English for International Communication (TOEIC).

But a number of people caught up in the response have protested their innocence.

The NAO's report said:

- For two years, the Home office revoked the visas of anyone with an invalid test, without expert assurance of the validity of voice recognition evidence

- In 2016, the Department's independent expert estimated that voice recognition checks would have identified substantially fewer than 1% of people of cheating incorrectly

- It is difficult to estimate accurately how many innocent people may have been wrongly identified as cheating

- Thousands of people accused of cheating have won the right to stay in the UK, with 4,157 "invalid" cases granted leave to remain

- Around 12,500 people appealed against immigration decisions, with 3,600 winning their cases

- The Home Office has not tracked the reasons why people have been allowed to stay - some disproved allegations of cheating, others have remained on human rights grounds

- In November 2017 the Home Office estimated it had spent £21 million dealing with the repercussions of TOEIC cheating

- As of March, 11,000 people who had taken TOEIC tests had left the country following the discovery of extensive cheating, although some may have left for reasons not related to allegations of deception in the tests

- As part of its response to the scandal, the Home Office has supported successful prosecutions against 25 "organised criminals"

Evidence "strongly suggests" there was widespread abuse of the Tier 4 student visa system, the report said.

It concluded: "It is reasonable based on the balance of probabilities to conclude there was cheating on a large scale because of the unusual distribution of marks, and high numbers of invalid tests in test centres successfully prosecuted for cheating.

"The courts found in 2016 that the department's evidence was sufficient to make the accusations it did.

"Nonetheless, the department's course of action against TOEIC students carried with it the possibility that a proportion of those affected might have been branded as cheats, lost their course fees, and been removed from the UK without being guilty of cheating or adequate opportunity to clear their names."

Public Accounts Committee chairwoman Meg Hillier said: "Worryingly, the Home Office made no effort to identify innocent people, and may have removed some from the UK who were not guilty of cheating."

Nazek Ramadan, director of Migrant Voice, said: "The way the Home Office has treated these students makes a mockery of the British justice system. And the impact has been devastating."

A Home Office spokeswoman said: "The report is clear on the scale and organised nature of the abuse, which is demonstrated by the fact that 25 people who facilitated this fraud have received criminal convictions."

By Hayden Smith