The UK is not under common law jurisdiction anymore. It's been under CORPUS-JURIS jurisdiction for quite some time.

That invitation to go for a taped interview seems dubious at best. Under common law there are no obligations answer any questions or otherwise incriminate yourself before commencing a trail before a jury of you piers. If they are using wording like allegations it seems they want you to waive your rights and trick you into incriminating yourself, basically do their job for them.

Tread very carefully Danny.

I'm not sure if I can post a link to youtube vid but the video has some specific details on the British transferal to CORPUS-JURIS jurisdiction and the abolition of common law that has since occurred worldwide. It includes an excerpt from a British doco on the topic starting about 8:54