'Doctor Who' bosses have a storyline that would pair the Time Lord with Harry Potter.
The idea was originally developed by former show writer Russell T Davies, who wanted the boy wizard to make an appearance in the 2008 Christmas special - but the ambition has subsequently been left on the shelf.
A source told The Sun newspaper: "Who knows if it will ever see the light of day? But the idea alone is amazing in itself.
"Combining two massive franchises like 'Harry Potter' and 'Doctor Who' would be incredible."
Davies' plan would have seen Harry Potter author J.K. Rowling contract a space bug that brought her characters to life.
The Doctor would have then battled Rowling's baddies in order to return them to the sphere of fiction once again.
Originally, Davies - who in 2007 got pop star Kylie Minogue to appear in the Christmas special - asked the acclaimed author to write an episode of the sci-fi show, but she rejected the offer.
In a leaked email, he said: "Reflecting we can't possibly get someone to star in next year's Christmas special who's as famous as Kylie, I thought, don't ask JK to write a Dr Who, ask her to be in a Dr Who!"
And, crucially, Davies' plan failed to receive backing from the then-Doctor David Tennant.
Davies admitted: "We've got to keep him happy."
Meanwhile, Steven Moffat, the current showrunner on the programme, who is leaving after the new series, admitted he is aware of Davies' ambition.
However, Moffat also suggested he wasn't interested in revisiting the idea.
He said: "It exists on a hard drive somewhere - but you'll have to ask Russell because that was in his time."