Afghan migrants were able to bring up to 22 family members each to the UK following a critical military data breach, according to a Telegraph investigation that has raised questions over national security and government transparency.

The breach, described as one of the most damaging in British history, exposed personal data of nearly 19,000 Afghans who had worked with or supported UK forces during the war in Afghanistan. The leak occurred in 2022 when a defence official mistakenly shared the list. Many of those named were considered high-risk targets for the Taliban.

In response, the UK government launched the Afghanistan Response Route in March 2023 to fast-track those at risk into Britain. However, according to The Telegraph, the emergency programme opened the door to thousands of additional family members — far beyond the original scope intended by ministers.

One migrant reportedly brought 22 relatives, while others were said to have brought numbers in the "high teens." Originally, the Defence Ministry had sought to limit accompanying family to spouses and children, but court rulings repeatedly broadened eligibility. Judges cited the European Convention on Human Rights to justify a more inclusive definition of "family."

A pivotal ruling in November 2023 by High Court judge Mrs Justice Yip declared that a "family member" need not have a blood or legal connection to the applicant. She acknowledged cultural interpretations of family, noting that “there is no requirement for a blood or legal connection.”

Court documents — previously sealed by a super-injunction issued at the direction of then Defence Secretary Sir Grant Shapps — were only made public this week. They reveal that while just 10% of additional family members had been deemed eligible before the data leak, estimates now suggest up to 12,500 additional family members could be approved, a more than fivefold increase.

The secrecy surrounding the case has sparked political backlash. Sir Grant had publicly stated he was "surprised" by the duration of the super-injunction, but The Telegraph reports he actively appealed a court’s attempt to lift it in May 2024, just before the general election.

Accommodation Crisis and Security Concerns

The influx has reportedly left UK officials scrambling for housing solutions. Some military bases were said to be modified — with two houses knocked into one — to accommodate unusually large family units.

According to The Telegraph, criminal elements may have exploited the confusion, with some individuals known for stealing from British military bases or even selling weapons to the Taliban allegedly making it into the UK — while some eligible ex-commanders were left behind.

The resettlement has reportedly caused major tension within government circles, as concerns grew over "bogus claimants" and potential threats to national security. Ministers were divided on how to manage the fallout from the data breach and the resulting surge in asylum-linked applications.

Despite the secrecy, the fallout from the breach and its political implications are now in full public view.