Former defence secretary Sir Ben Wallace said he makes “no apology” for stopping the reporting of a leak that revealed data about thousands of Afghans who had supported British forces.

Writing in the Telegraph, Sir Ben said the decision to apply for an injunction was “not a cover-up”.

In February 2022, the details of nearly 19,000 people who had applied to move to the UK under the Afghan Relocations and Assistance Policy (Arap) were leaked. The previous government learned of the breach in August 2023 when some details were posted on Facebook.

Sir Ben said when he was informed of the error he was “determined that the first priority was to protect all those that might be at risk”.

“Some may disagree but imagine if the Taliban had been alerted to the existence of this list. I would dread to think what would have happened,” he added.

A new resettlement scheme – the Afghanistan Response Route – was set up in April 2024 for those on the leaked list. About 4,500 Afghans have arrived in the UK so far.

The scheme is understood to have cost around £400m, with a projected final cost of about £850m.

Details of the major data breach, the response and the number of Afghans granted the right to live in the UK as a result only came to light on Tuesday after a High Court judge ruled the gagging order should be lifted.

The leak contained the names, contact details and some family information of people potentially at risk of harm from the Taliban.

The daughter of an Afghan translator whose details were leaked told the BBC’s Newsnight programme that her whole family “panicked”.

“No one knows where the data has been sent to – it could be sent to the Taliban, they could have their hands on it,” she said.

Her grandmother, who is still in Afghanistan, is “completely vulnerable”, she added.

Downing Street would not confirm whether the official responsible for the leak had faced disciplinary action, with a spokesman saying they would not comment on individuals.

Speaking in the commons on Tuesday, Defence Secretary John Healey said the person involved in the leak was “no longer doing the same job”, and offered a “sincere apology” on behalf of the government.

Conservative leader Kemi Badenoch has also apologised on behalf of her party.

Former Conservative leader Sir Iain Duncan Smith said Parliament should have been informed about the leak.

He told the BBC’s World Tonight: “Parliament cannot be ignored for that length of time, we owe a duty to the public to at least have examined this.”