security

Other agency errors included an unchecked software bug that led to Terrorism Act detentions

Thousands of GCHQ storage drives containing sensitive data have been lost for years, and the British signals intelligence agency still cannot explain where they are.

According to the Investigatory Powers Commissioner’s Office’s (IPCO) annual report , the missing storage drives have been known to officials for years, and may contain data related to the Investigatory Powers Act (IPA) .

"I remain concerned that GCHQ has not yet established a sufficiently clear understanding of the scale, location, and recoverability of lost removable media that may contain IPA-related data, notwithstanding that the underlying issues were first drawn to my attention several years ago," wrote investigatory powers commissioner Lord Brian Leveson.

"While I recognize the technical and practical challenges involved, the passage of time without a comprehensive account heightens the importance of sustained senior focus and assured…