I saw this first in the print edition of the Aberdeen Press and Journal, and have been able to find only sparse information on the Internet.
The Yorkshire Evening Post reports that Terrence Robert Gavan has been remanded in custody after appearing at the Old Bailey under Section 58 of the Terrorism Act – having weapons and having or collecting information which could be useful to a terrorist – as well as a number of firearms offences. Court records can be found here, and relates to a joint Police and Army operation on 21 May.
I am unable to find any confirmation of what groups the accused is alleged to be connected with, so do not feel confident in speculating. I would be interested to know more.