Whistleblower testimony and official documents obtained by BBC Newsnight reveal the Home Office has continued to try to remove people based on the claims of the international testing organisation ETS - despite knowing of serious concerns about its conduct and flaws in its data.
More than 2,500 people were deported and at least 7,200 more were forced to leave Britain after ETS accused them of cheating in an exam it set and marked. Others who remain in the UK continue to fight to clear their names after enduring years of hardship. Cheaters are accused of falsifying exams so people could falsely obtain a pass they could use to apply for a visa.
ETS provided the government with a list of alleged cheats - but despite proof that this included some innocent people who had been wrongly accused, the Home Office continues to stand by ETS's evidence.