Turns out Paddy Power tweeted "Hmm. Rumour mill is whirling round again. Told there is a big racing story breaking imminently and it's nothing to do with the National." Everyone then started tweeting it must be Frankel and it all went from there.
Frankel went out today second lot.
He is having a precautionary scan which you have to do once the swelling has subsided to get the clearest picture. He over-reached his hind foot onto his front leg which caused the leg to fill/swell (most likely soft tissue swelling/bruising). In most cases you wouldn't bother to scan but wisely they do not wish to take any chances.
I gather he was ridden whether that incorporated walking or cantering I am not sure but I can find out.