Former MI5 contractor 'leaked sensitive information to foreign state during grievance while mentally ill' Old Bailey hears

A BITTER former MI5 contractor worker leaked sensitive information to a foreign state before travelling to try to Latvia to arrange a face-to-face meeting at an embassy, the Old Bailey heard.

Juan Joseph, 42, a former government IT contractor is alleged to have breached the Official Secrets and National Security Acts at the same time as pursuing a grievance against MI5, while suffering mental health issues.

Some of the trial before Mr Justice Hilliard is being heard behind closed doors with the public or press excluded due to national security issues.

Joseph worked as an IT contractor for MI5 from September 8 2009 and October 30 2020 and had some insight into MI5 capabilities and privileged access to information of “the highest classification”, the court heard.

Opening the trial, prosecutor Jocelyn Ledward KC, said: “In late 2024 and early 2025, whilst undoubtedly mentally unwell, he sent a number of emails, addressed to or copying into his communications bodies representing one or more foreign countries.

“Those emails contained information which the prosecution say should not have been disclosed in that way, the disclosure of which was damaging to UK national interests.

“He also travelled to Riga in Latvia and by email asked to meet with representatives of the embassy of another country there in a way that indicates he was intending to and preparing to make further such disclosures.”

His mental illness took hold in 2020, the court heard, with a decision made to remove his vetting and security clearance and his contract was terminated when he signed a declaration binding him to the terms of the Official Secrets Act.

He then went on to raise a number of grievances against MI5, and launched court action, including applying for a judicial review at the High Court, when he copied an email to the court to a foreign state on November 19 2024, the court heard.

Then, on December 8 2024, Joseph travelled to Riga and was stopped by police at Gatwick Airport on his return on December 15.

From five mobile phones and two computers seixed from him, police recovered two photographs allegedly taken by Joseph near the embassy of the foreign state in Riga.

Officers also found Joseph had sent two emails to the same embassy requesting a meeting while in Riga.

He allegedly disclosed information to the state that which was protected under the National Security Act.

Ms Ledward said: “It is clear from those two emails that the defendant’s trip to Riga and was for the purpose of attempting to make physical contact with representatives of the foreign state through their embassy in Riga in order to disclose protected information to them.”

There was further sensitive information sent in an email on January 13 2025, before he was arrested on January 30 2025 at an Ibis Hotel near his home in Sutton, south London.

Police found a folding lock knife in his jacket pocket, the court heard.

At his home a homemade card purporting to be MI5 identifiction was found.

Joseph denied disclosing anything he should not have in interview and claimed to be still working for the security service remotely.

He has pleaded not guilty to obtaining or disclosing “protected information” and “preparatory conduct” with the intention of committing acts constituting an offence contrary to the National Security Act 2023 and possession of an offensive weapon.

On Friday, March 13 2026, MI5’s former head of HR gave evidence from behind a screen about the grievances Joseph made and his mental state, which declined with extreme anxiety and paranoia from August 2020, the witness said.

He was referred to St Thomas’ Hospital in London but discharged himself before he could be assessed.

The trial continues.