MI5 presented evidence based on falsehoods to three courts while defending a violent neo-Nazi informant, according to a highly critical official report. The investigation, led by deputy investigatory powers commissioner Sir John Goldring, found that senior MI5 figures and the agency itself made serious errors. The report confirms previous BBC revelations from February last year that MI5 had lied to the courts, an assertion the security service had strongly denied. Sir John's investigation was commissioned by the prime minister in September after the High Court rejected MI5's explanations regarding the matter as inadequate and unreliable. The report's conclusions could lead to contempt of court proceedings or even criminal prosecution for the agency. MI5 Director General Sir Ken McCallum acknowledged the gravity of the failings, stating, "MI5 recognises without hesitation the seriousness of our failings in these proceedings. I repeat my previous apologies to both courts for the incorrect evidence that was provided, and for our slowness in recognising what had happened." Home Secretary Shabana Mahmood described the findings as "stark," noting that the report details "serious failings by individual MI5 officers, resulting in false evidence being provided to the courts, and criticism of MI5 as an organisation." She added, "I am taking urgent action to hold MI5 to account for these failures, including strengthening my oversight and assurance of their work." The inquiry examined how MI5 provided untrue evidence to three courts concerning its adherence to the 'neither confirm nor deny' (NCND) secrecy policy regarding the agent status of the neo-Nazi informant. MI5 had claimed it maintained NCND, which allowed it to withhold information from a woman abused by the informant. However, this was untrue; MI5 had actually disclosed the man's agent status to the BBC in phone calls in 2020 while attempting to dissuade an investigation into him. A senior MI5 officer, identified as Officer 2, is found to have repeatedly lied, forming the basis of MI5's inaccurate court statements. The report states Officer 2 presented a "wholly fictitious account" denying he had ever informed the BBC that the agent was indeed an MI5 operative. A separate senior MI5 officer, Officer 3, is accused of misleading his colleagues and not acting in good faith. The report assigns him significant responsibility for the continuation of MI5's falsehoods, stating he misrepresented what Officer 2 had told him and was untruthful about warnings he received from colleagues. An MI5 deputy director, Witness A, is also implicated for overstating matters during a key internal meeting and providing a misleading note of his comments, thereby contributing to the agency's continued reliance on the false account. The report indicates that various individuals within MI5 were aware that the NCND policy had been departed from.