Three judges have decided not to pursue contempt of court charges against MI5 or its staff, despite the spy agency admitting it gave false evidence to three courts, the High Court ruled on Tuesday.
The judges, led by Lady Chief Justice Baroness Sue Carr, said a contempt case would be too complex for the court to manage and not in the public interest to pursue. They suggested instead that police investigate whether individual MI5 officers committed misconduct in public office or perverting the course of justice.
MI5 gave false evidence in cases involving an informant known as Agent X, who engaged in domestic abuse and is described as a violent neo-Nazi. The false evidence concerned whether MI5 had maintained its policy of neither confirming nor denying information about the agent's status.
An investigation by Sir John Goldring, ordered by the prime minister, concluded in July that one senior MI5 officer lied repeatedly while another misled colleagues and lied about what he was told. That investigation also found "serious and systemic failures in MI5's conduct." MI5 accepted the findings in September without reservation.
The two officers most criticised deny dishonest conduct. One has resigned from MI5. The other is facing internal disciplinary proceedings.
MI5 chief Sir Ken McCallum said the court's decision was welcome and repeated his apology for the failures and "additional distress" caused to the victim, known as Beth.
The Home Office said it is "still considering the implications of the judgment" regarding whether to refer the matter to police for criminal investigation.