London has admitted mistakenly sharing the personal data of more than 250 Afghans who worked for British forces and are seeking to resettle in the UK.
The UK's Ministry of Defence copied them into an email, allowing all recipients of the message to see their names and photos sometimes associated, according to the BBC.
The ministry has apologised to "all those affected" and announced it was opening an investigation.
Several politicians lashed out at the government over the incident, highlighting that many Afghans who collaborated with NATO forces fear for their lives under the Taliban.
Conservative MP Johnny Mercer said the Ministry of Defence is responsible for "criminally" letting them down, adding that the incident will force them to change housing in order to avoid repercussions.
Criticism also came from the opposition, with shadow secretary John Healey accusing the government of having "needlessly put lives at risk".
The data blunder comes after prime minister Boris Johnson, in August, announced a resettlement scheme for around 20,000 Afghan refugees, with priority given to those "threatened by the current crisis".