It was seen, at first, as a backlash. When online threats emerged at the weekend to release naked photographs of the actor Emma Watson,many felt it was a hostile response to a barnstorming speech the Harry Potter star had just given to the UN about women’s rights.

But in a series of bizarre twists, a website claiming to belong to an online marketing company said on Wednesday that it had made up the threat as a publicity stunt to shut down the notorious messageboard 4chan – only for further claims to emerge that the entire episode was the work of hoaxers. In fact, neither the marketing company – nor the naked photographs – appear to exist.

What now appears to be a tasteless online spoof first emerged on Saturday, when a website entitled EmmaYouAreNext.com appeared featuring an image of the actor next to a countdown.