END OF STORY.
While I was making these postings I also filed an official Incident Report with the airport manager and a separate one with The Hellenic CAA requesting to know what regulations had changed, what the new regulation was and specifically what I needed to do to be able to fly again as soon as possible. I didn't actually get a reply to either Incident Report but 4 days later I received a phone call from the Head of Security apologising for a "misunderstanding on his part that had caused confusion" and confirming that I was indeed allowed to fly and already had all the necessary clearances and licences.
