We're not saying he did, but the rumour is out there.
We know of this rumour. It is just a rumour, but there may be truth to it like there has been to previous rumours we knew were rumoured to rumour.
Banquo's Ghost must have known about the rumour. Of course after the rumour became public, he denied all involvement. Hey, who wouldn't?
The real question is:
Why hasn't Banquo's Ghost issued a formal denial before the rumour started???
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