MI5's False Evidence in Neo-Nazi Spy Case a 'Serious Failing', Says Watchdog
Investigatory Powers Commissioner Lord Leveson described the agency's conduct as 'as serious as anything' he has dealt with.
The oversight commissioner for the UK's intelligence services has stated that MI5's submission of false evidence to multiple courts in a case involving a violent neo-Nazi informant represents a "serious failing" and is "as serious as anything" he has encountered during his tenure.
Lord Leveson, the Investigatory Powers Commissioner, made these remarks following an investigation by his office, the Investigatory Powers Commissioner's Office (IPCO), into how MI5 provided misleading information to three courts regarding an informant referred to as 'agent X'. IPCO's report, released earlier this year, detailed instances of repeated deception by one senior MI5 officer and falsehoods from another regarding their interactions.
The investigation also identified "serious and systemic failures in MI5's conduct" across the case. MI5 has since accepted the report's findings "without reservation." The High Court is expected to rule soon on potential actions against the agency or its personnel.
Lord Leveson emphasized that "oversight depends on candour" and that "failings of candour undermine the entire basis of oversight and accountability." He confirmed that his investigation found that both IPCO and the courts had been misled.
The case centered on MI5's alleged breach of its 'neither confirm nor deny' (NCND) secrecy policy concerning the agent status of the neo-Nazi informant. This informant was known to have coercively controlled his partner, identified by the alias Beth, and had attacked her with a machete. MI5 reportedly facilitated his travel abroad for intelligence work even while he was under police investigation.
MI5 had claimed it maintained the NCND policy, which allowed the courts to grant anonymity and withhold information from Beth. However, evidence revealed that MI5 had, in fact, disclosed the informant's status in calls to the partner's legal representative in 2020, attempting to dissuade an investigation. A senior MI5 officer was found to have repeatedly lied about the informant's extremist leanings and abusive behavior, and even sought to arrange a meeting with the informant, deviating from the NCND policy.
This officer has since resigned from MI5. The BBC initially exposed the case in 2022, prompting a failed legal attempt by the government to block the investigation.
Beyond the agent X case, IPCO's annual report also highlighted other concerns. Errors involving agents within MI5 increased from four in 2017 to 21 in 2025, while MI6 saw a decrease from 10 to three in the same period.
The report also criticized the National Crime Agency (NCA) for mismanagement of a juvenile informant. The NCA failed to report running a child informant within the required timeframe to Lord Leveson, and a senior officer extended authorization beyond legal limits. The child was allegedly tasked with criminal conduct without proper legal safeguards.
Lord Leveson stated that the NCA's conduct fell "well short of what the law requires" and has communicated his concerns to the agency's director general.
Additionally, GCHQ faces ongoing scrutiny regarding "thousands" of missing portable media items, such as memory cards and hard drives, that may contain sensitive data. Lord Leveson expressed significant concern about the delay in GCHQ's investigation into the matter.