Former defence secretary Sir Grant Shapps has defended the decision to keep secret a data breach involving the details of thousands of Afghans and some British officials.

In his first interview since it became public, Sir Grant told the BBC erring on the side of caution was “entirely justified”, adding his focus had been “sorting out the mess and saving lives”.

Many people were judged to be at risk of serious harm or even death as the Taliban sought retribution against those who had worked with the British government during the conflict.

He said the injunction blocking reporting of the breach was “quite rightly” applied for by his predecessor and he believed at the time it should stay in place.

A “super-injunction” – a kind of gagging order that prevents the reporting of even the existence of the injunction – was lifted earlier this week.

Sir Grant was appointed as defence secretary in August 2023 – shortly after the breach was discovered and just before orders were put in place by the courts preventing it from being made public.

He told BBC Radio 4’s Today programme that “faced with the choice of whether that list would get out and people would be pursued, murdered and executed as a result of it, or doing something to try and save those lives, I’d much rather now be in this interview explaining why a super-injunction was required, than being in this interview explaining why I failed to act and people were murdered”.

He added he was surprised the order lasted so long and that he had thought, as the risks started to lessen, it would have ended last year.

Sir Grant was also asked why the Intelligence and Security Committee, which scrutinises the security services, was not informed, to which he replied “even a hint of this getting around…meant the risks were incredibly high”.

“The ‘who was briefed’ was decided by conversations with the judges,” he said, adding: “You can argue that circle should be wider”.

The data of nearly 19,000 Afghans who had worked with the British during the 20-year war in Afghanistan and had applied to resettle in the UK were inadvertently leaked in February 2022.

The details of over 100 Britons were also released, including spies and special forces.

After the lifting of the super-injunction on Tuesday, a secondary injunction had prevented the revelations about UK special forces and security services personal being compromised.

But that was also lifted on Thursday when barristers representing both the MoD and a group of media organisations reached a compromise that meant journalists could report the additional facts.

The Liberal Democrats said Defence Secretary John Healey appeared to have misled Parliament, after he told MPs on Tuesday that to the best of his knowledge no serving member of the armed forces had been put at risk by the loss of data.

Downing Street said Healey was accurate when he addressed the Commons, with the prime minister’s official spokesperson adding: “We take the security of our personnel extremely seriously.”

A spokesperson for the Ministry of Defence (MoD) said: “It’s longstanding policy of successive governments to not comment on special forces.

“We take the security of our personnel very seriously and personnel, particularly those in sensitive positions, always have appropriate measures in place to protect their security.”

It’s understood that the UK armed forces personnel affected by the leak were provided with additional security advice.

Those serving in the special forces and secret services already have heightened protection measures.

The breach was not discovered by the government until August 2023, when someone in Afghanistan who had obtained the data posted part of it on Facebook and indicated he could release the rest.

The discovery forced the government to covertly set up the Afghanistan Response Route (ARR) – a resettlement scheme for those affected, who were not told about the breach despite the risk to their security.

The scheme has already allowed 4,500 Afghans and family members to move to the UK and a further 2,400 people are expected, at an estimated cost of £850m.

The accidental leak was the result of someone working at UK Special Forces headquarters in London inadvertently emailing more than 30,000 resettlement applications to an individual outside of government, thinking that they were sending data on just 150 people.

The MoD has refused to say how many people in Afghanistan may have been harmed as a result of the data breach.

The Taliban government said on Thursday that it had not arrested or monitored Afghans affected by the leak.

But relatives of Afghans named in the leak told the BBC that they fear for their families still in the country, with one saying efforts by the Taliban to find their named relative intensified following the leak.