Data breach lawyer Sean Humber confirmed Leigh Day was investigating a group claim from Afghans, some of whom remain in Afghanistan, as well as others who have relocated to the UK. Mr Humber told the Express that those still in Afghanistan could be due higher compensation.

The former defence secretary says erring on the side of caution was "entirely justified" after the 2022 breach.

Over 18,000 Afghan citizens eligible to relocate to the UK under a government programme to protect them from the Taliban were put at risk in a heretofore unreportable data breach.

More than 16,000 Afghans were secretly brought to the UK in largest covert peacetime evacuation after MoD put them in danger of being targeted by the Taliban. Social affairs correspondent Holly Bancro

The identities of more than 100 British officials, including members of the special forces and MI6, were compromised in a data breach that also put thousands of Afghans at risk of reprisal, it can be reported. The latest fallout from the breach was kept secret by an injunction until Thursday, when the order was lifted in part by a High Court judge.

Sean Humber, from law firm Leigh Day, said that a data breach of thousands of Afghans’ personal information was ‘catastrophic’.

Our community has reacted with anger, disbelief and deep concern to revelations that a catastrophic Ministry of Defence data breach, which put tens of thousands of Afghans at risk, was kept hidden under a superinjunction for nearly two years,