I got another email not long after the call, which I think was directly from the lady I spoke to:
Thank you for contacting Amazon.co.uk.
My name is XXXX and I work in the customer escalation team.
Further to our telephone conversation, you vigilance in reporting the items you believe to be inappropriate and possibly illegal is very much appreciated. We take matters like this very seriously, and can guarantee you that the matter is being looked in to.
As you can see, the item in question is now showing as 'Currently unavailable' which means that no orders can be placed for it at this time. Although the shirt has not been completely removed from the website, it also cannot be ordered.
You are welcome to check in from time to time on the website to see if the status changes. Unfortunately, we will not be able to notify you when a decision is made regarding this item.
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It's true that the T-shirt has been shoiwing as unavailable for several days.
However, it's unclear why the 30-odd negative reviews of it have recently been removed, with the one positive review remaining, plus two more negative ones filed since, giving the average star rating as much higher than before! Gah!