Only hours after Paul the psychic octopus swam his way into the netherworld, conspiracy theories about his demise began to emerge.

Paul, who gained fame by predicting World Cup football results, died on Tuesday at home in his aquarium in Oberhausen, Germany.

But Jiang Xiao, the director of a forthcoming thriller, Who Killed Paul the Octopus? claims the creature died before the final of the World Cup had been played, and had been secretly replaced by his keepers.

"[Octopuses] all look the same. It is impossible to tell the difference," she told the Guardian last night.

"For the movie, we had done quite a lot of investigation and I am 60 per cent to 70 per cent sure that Paul died on July 9 [two days before the World Cup final] and the Germans have been covering up his death and fooling us for a long time."

Jiang declined to explain why she believed Paul had died in July - or to say more about the revelations in the movie. But she said the aquarium had become nervous after hearing about her project.

A spokesman for the aquarium denied the claim. "It's certainly not true that Paul died in the [northern] summer."

- Staff reporter