They have a fucking cheek don't they. Same thing with the Dutch AZ vaccine supplies.
Not approved in the EU
Banned in France (because they hate us, no other reason)
Banned in Germany and other EU countries
Hissy fit because AZ choose send it to the UK rather than to EU countries to let it rot on the shelves. Wankers.
I think it's not quite that simple...
On the specifics, sites (and sometime specific production lines, dependent on the details) have to be authorised by regulatory authorities before they can release product to patients. MHRA for the UK, EMA for Europe, FDA for USA etc.
This applies both to the drug substance (in this case, bulk vaccine) and finished product (in this case filled vials).
Drug substance is made at a number of different sites, and filled into vials at many more.
In the EU, there are two drug substance sites for AZ, one in Belgium, and one in the Netherlands.
As I understand it (and I could be wrong) the Netherlands site has not yet been approved by any regulatory authority for production of this vaccine. The Italian site, which fills the vials, has been.
It appears that some or perhaps all of this stock is manufactured from Netherlands drug substance, and quarantined waiting approval of that site before it can be shipped anywhere. Describing it as "hidden" is likely to be journalistic hyperbole, to put it politely.