This article is more than 1 year old

This article is more than 1 year old

The home secretary has applied to the high court for a secret hearing to prevent public disclosure of the nature of “serious” breaches recently admitted by MI5 in its surveillance safeguards.

In a seven-page submission, Sajid Javid requested the court hold what is known as a “closed material procedure” – from which the claimants, the media and public will be excluded – into failures by the intelligence agency in its “internal” handling of intercepted material.

The court was told on Monday that the agency’s compliance problems were still continuing, involved daily conversations with the regulatory oversight body, the Investigatory Powers Commissioner’s Office, and may affect several other areas of operations.

Last week Javid said in a written parliamentary statement that MI5 had identified and reported compliance risks “within certain technology environments used to store and analyse data, including material obtained under the Investigatory Powers Act”.

Ben Jaffey QC, representing the civil rights organisation Liberty, told the court that little information had been made available. “We are not told how many people are affected, whether those are people of intelligence interest or whether it’s a [large-scale] data breach,” he said.

Gerry Facenna QC, for the Home Office, said the data breaches related to the agency’s “internal handling arrangements” of material intercepted under warrant. “Other risks have been identified,” he added. “There are daily interactions between MI5 and the Investigatory Powers Commissioner’s Office.”

The submission signed by Javid says the case involves “sensitive material” and adds: “MI5 is also investigating the potential for similar compliance risks, although on a much smaller scale, within two discrete areas of another technology environment used by MI5.

“If similar compliance risks are found to exist in these areas, they may also require immediate mitigation … I have concluded that such material cannot be disclosed in open [court] because of the damage such disclosure would cause to the interest of national security.”

Lawyers for Liberty said the request for a closed material procedure hearing had come at a very late stage.

Megan Goulding, a lawyer at Liberty, said: “This is a clear-cut example of how the supposed safeguarding and oversight system is failing to protect us from the excessive and unwarranted surveillance and data retention powers created under the ‘snooper’s charter’.

“The breach in itself is deeply concerning but on top of that the way this has unfolded – with IPCO only finding out because MI5 reported it, and the wider public only knowing apparently because of our legal case – shows how fatally flawed the oversight system for security services is.”

Lord Justice Singh, the judge hearing the application, did not rule on whether or not there should be a secret hearing.

The National Union of Journalists has intervened in the case, which is due to be heard in full over five days next month.