MI5 and its staff will not face contempt of court proceedings, senior judges have ruled, even after the spy agency admitted to lying in evidence presented to three courts. The decision comes after a complex investigation into the agency's conduct concerning an abusive informant, codenamed Agent X.

In a ruling delivered on November 3, 2026, three senior judges, including Lady Chief Justice Baroness Sue Carr, determined that pursuing a contempt case would be too complex for the court to manage effectively. They stated that it is not in the public interest to proceed with contempt proceedings, suggesting that the police possess the necessary investigatory powers and resources to handle the matter. This leaves open the possibility of individual MI5 officers facing investigation for misconduct in public office.

The false evidence provided by MI5 related to communications between the agency and the BBC concerning Agent X, an informant whose alleged abuse was being investigated by the broadcaster. MI5's chief, Sir Ken McCallum, acknowledged the court's decision, stating that the judgment underscores the agency's "serious failures in this case." He reiterated his apology for these failures and the "additional distress" caused to an individual referred to as Beth.

The court's decision follows an investigation ordered by the prime minister and conducted by Sir John Goldring. This inquiry, concluded in July 2026, found that one senior MI5 officer repeatedly lied, while another misled colleagues and misrepresented information. The report also criticized other senior spies and identified "serious and systemic failures" in MI5's conduct. In response, MI5 stated in September 2026 that it accepted the report's findings "without reservation."

While the two most criticized MI5 officers deny dishonest conduct, one has resigned from the agency, and the other is undergoing internal disciplinary proceedings. The head of MI5's watchdog, investigatory powers commissioner Lord Leveson, described the case as "as serious as anything he has faced in his role."

Despite the gravity of the admitted falsehoods, the High Court has opted against initiating further action against the two individual officers or against MI5 and its director general on a corporate basis. The judgment acknowledges sufficient evidence exists to potentially initiate contempt proceedings against the officers but reiterates that it is not in the public interest.

The court's reasoning highlights the unmanageable investigative aspects of a contempt process, suggesting it would largely duplicate the findings already made by Sir John Goldring's inquiry. The judges indicated that any further action should be pursued through a police investigation.

This case has significant implications for accountability within intelligence agencies. The decision not to pursue contempt charges, while citing complexity and public interest, may raise questions about the extent to which such agencies can be held directly accountable in court for providing false evidence, especially when alternative investigative avenues exist.