Judoon to return in Series 4?

The picture above was made by me and is copyright Doctor Who Insania
When the Judoon hit our screens last year, I like many fans of the show took to them very well and I have been hoping that we might see them again in the near future well I my hopes have been answered so for me the big question is will the Judoon return to Doctor Who in Series 4, well I might just have the answer.
In Cardiff at the Doctor Who exhibition the Judoon costume and stand have been replaced with a sign stating that they were taken awaay for filming in Series 4 of Doctor Who, so will the intergalactic police be back for more action or is this a simple mistake?
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