rennie street
Samata Ullah, 34, lived in a terraced house along this street in CardiffGoogle Streetview

A cyber-jihadi who stored Isis material on a James Bond-style USB stick disguised as a cufflink is facing jail after pleading guilty to five terror offences.

Samata Ullah, from Cardiff, admitted being a member of Isis and to charges of terrorist training, preparing terrorist acts and possessing articles for terrorist purposes.

The 34-year-old former insurance worker was a member of a group calling itself the Cyber Caliphate Army, which gave fellow violent jihadists advice on how to hide their communication from the authorities using encryption techniques.

At the time of his arrest in September last year, Ullah was found in possession of a USB cufflink loaded with a Linux operation system to conceal a hoard of extremist data, Press Association reported.

The court also heard how, from December 2015, Ullah had provided instructional videos on how to secure sensitive data and remain anonymous online by using Tor and PGP (Pretty Good Privacy) encryption.

Ullah, a British national of Bangladeshi heritage, would wear gloves and use a voice modification system to hide his Welsh accent in the videos.

He also pleaded guilty to having a PDF version of a 500-page book titled Guided Missile Fundamentals AFM 52-31 and another called Advances in Missile Guidance, Control and Estimation, for terrorist purposes.

In one message about the manuals, Ullah wrote: "Ask the brothers in Turkey and Dawlah whether the book would be useful for them. I have bought a copy and I want to scan all 500 pages and send it to them so that they can start learning the basics of rocket design.

"It can also be translated into Arabic to form the basis of our future weapons programs."

In another message, he wrote: "We should also [try] recruiting people from Turkish and Pakistani defence companies as Turkey and Pakistan already have the technology needed to destroy or jam drones and planes – but that takes stealth as you don't want to approach them saying: 'Hi, we are Isis, do you want to work for us?''

Ullah had admitted all but one of the charges against him earlier this month, but his pleas could not be reported until the prosecution had decided whether to pursue a trial for the remaining allegation of directing terrorism.

During a hearing at the Old Bailey on Monday (20 March), Brian Altman QC, prosecuting, said the crown had accepted the pleas after referring them to the attorney general. He asked for the remaining charge to lie on file.

Ullah, who has since been diagnosed with autism, is due to be sentenced on 28 April.