A former defence worker breached the Official Secrets Act when he allegedly leaked details of a UK missile system “upon which the security of the realm partly depends”, a court heard.
Simon Finch, 50, from Swansea, is accused of sharing technical details classified as “top secret”.
He denies recording and disclosing secret defence information and refusing to give authorities access codes to three electronic devices.
Mr Finch is on trial at The Old Bailey.
The jury heard how the software engineer had worked for companies, including BAE Systems and QinetiQ, contracted to provide services to the Ministry of Defence, from the late 1990s until 2018.
In October 2018, it is alleged he sent an email to eight recipients including law firms, charities, trade unions, an MP and a US citizen, containing classified information he had accessed.
It detailed operational information about the weapons system, which is still in use by the armed forces, the court heard.
An expert damage assessment found the release of the information could give “a hostile adversary of the UK… an understanding of the function” of the system and “methods of countering it”, prosecutor Mark Heywood said.
The prosecutor said the email outlined technical detail about systems “on which the security of the realm partly depends”, that are classified as “secret and top secret”.
He described how Mr Finch’s health had begun to deteriorate after two assaults and in 2016 he had pleaded guilty to possessing an offensive weapon and a bladed article, for which he received a suspended sentence.
In the 2018 email, Mr Finch made claims of mistreatment that “amounted to torture” at the hands of the police and alleged he had been let down by various organisations including his employer, the court heard.
“His lack of redress and refusal of justice led him to the conclusion that he should not care for national security if the nation had no care for his security,” said Mr Heywood.
Jurors will hear more details about the system during closed sessions of the court, with journalists and the public not allowed into proceedings.
The trial continues.