
The watchdog charged with holding MI5 to account rewrote a report into the handling of a violent neo-Nazi agent after the Security Service gave it false information, the can reveal.
An early draft of the report by the Investigatory Powers Commissioner’s Office (IPCO) contradicted false evidence given by MI5 to court, but the final version did not.
IPCO told the it was “misled” by the Security Service.
MI5 director general Sir Ken McCallum apologised to IPCO, after the challenged the Security Service’s false statements to the courts.
The revelation means that MI5 has effectively given false evidence in this case to every organisation or court which is supposed to have access to the Security Service’s secrets and is responsible for holding it to account.
It also raises questions about how easily IPCO accepts false assurances from MI5, when it is supposed to ensure the Security Service works within the law and in the public interest.
IPCO began its secret investigation into MI5’s handling of the agent – a genuine neo-Nazi known publicly as X who informed on extremist networks – in 2022.
It was prompted by a story about how X used his Security Service role to coerce and terrorise his then-girlfriend, known publicly as “Beth”.
MI5 had told me he was an agent in 2020 while trying to stop me running a news story about the man’s extremism. I had already heard he was an agent, also known as a covert human intelligence source (Chis), and told MI5 as much.
The calls were an attempt by MI5 to protect and cover for X, a violent misogynistic abuser with paedophilic tendencies. Telling me he was an agent was inconsistent with MI5’s public claims about always abiding by a core secrecy policy – known as neither confirm nor deny (NCND) – on the status of agents.
But the Security Service maintained it had stuck by the NCND policy – first in a court case where the government tried to prevent the from publishing a story about X, and then in two further courts where Beth made a claim against MI5.
Keeping X’s status officially secret meant that key evidence was withheld from Beth.
IPCO’s role is to inspect the use of investigatory powers by MI5, such as its use of agents, and to identify any concerns in its reports.
It reviewed MI5 documents about the case of agent X, including an official record authorising a departure from NCND, and sent a draft report to MI5 in February 2023.
The report concluded that MI5 had taken the “extraordinary” decision to depart from NCND on X’s agent status in calls with me.

But MI5 pushed back and denied it had departed from the policy, including in correspondence with the Investigatory Powers Commissioner himself Sir Brian Leveson, a former High Court judge best known for chairing a public inquiry into the culture and standards of the media.
MI5 told IPCO: “We would like to make clear that we did not in fact take any such decision. [X’s] status was not disclosed to the either at that time or subsequently.”
In December 2023 Sir Brian wrote back, saying that “based on the records available” it was “entitled to conclude as a justifiable inference, on the balance of probabilities, that MI5 disclosed [X’s] role as a CHIS”.
He said that MI5 had provided no documentary evidence to support its position, nor any explanation about how it had convinced me not to run a story about X, as the Security Service had claimed.
“I note that MI5 has not disputed that disclosure was, at least, contemplated… either there was inadequate record keeping or there has been a failure to make records available to inspectors. Either would represent a serious compliance failure,” he said.
MI5 refused to back down and IPCO changed its position, with the final report falsely saying that there was no departure from NCND.

The final version introduced three significant falsehoods.
First, the report said that “an operational plan was agreed that there would be no disclosure that X was an MI5 CHIS”. This was the opposite of the truth. MI5’s entire operational plan involved a sustained attempt to persuade me to stop doing a story by disclosing that X was an agent.
Second, the report said “it was not MI5 policy to record all such exchanges” with journalists. This was untrue. There was a policy requiring such exchanges to be recorded.
Third, the report referenced a High Court witness statement I had given and said: “De Simone’s witness statement confirms that no disclosure of X’s status as a CHIS was made.” This was false. My witness statement said no such thing.
When contacted by the , IPCO said it was “misled into amending our draft report to remove the finding that Agent X’s status had been disclosed.”
IPCO said the first two falsehoods were included due to “assurances provided by MI5” and that it is now “clear that this information was incorrect and that the findings in our draft report reflected the true position”.
Regarding the false information about my witness statement, IPCO said: “We accept that this line in the report reflects our interpretation of your statement based on the information available to us at the time.”

The challenged MI5 on its false evidence late last year, leading to the Security Service apologising in the High Court. MI5 promised to transparently investigate what happened, and produced new witness statements from the senior officer in charge of the MI5 team who handled X and MI5’s director general of strategy – who is in effect third-in-command of the Security Service.
But neither of them told the court about the IPCO reports, even in the closed, secret part of the case intended to allow MI5 to disclose sensitive evidence.
The judge, Mr Justice Chamberlain, only learned about the IPCO report after he had made MI5 hand over another secret document which mentioned it.
MI5 made further witness statements apologising to the court, with the senior officer in charge of the team who handled X saying that “on reflection” they recognised the “IPCO issue” should have been revealed earlier.
“I apologise for not recognising the importance of explaining the IPCO aspect,” the director general of strategy said, but he insisted there had been no “attempt to conceal or obscure that aspect of the background”.
The was only told about the IPCO issue last week, with further information then provided after MI5 abandoned an attempt to keep applying its NCND secrecy policy on X’s agent status.
Following a High Court hearing on Tuesday, a panel of senior judges is considering what to do next about MI5’s false evidence.
MI5’s internal review into the false evidence said it was a result of mistakes, poor memories and bad record-keeping.
The said there is evidence of lies by MI5 officers, the internal inquiry was lacklustre and MI5 tried to keep damning material from the court.
IPCO said its investigation of how MI5 had managed Agent X found a “critical failure to create and maintain accurate documentary records; a finding which was reinforced in the final report due to MI5’s inability to produce any contemporaneous records and the length of time taken to respond to our requests for supporting evidence”.
In IPCO’s most recent annual report, published in the past few days, Sir Brian referred to Agent X, saying: “Recent developments in this case mean that we are keeping it under review.”