UPDATE: Alan Cumming has taken to the radio waves (via X-Men Films.com) to say that he hasn't been asked back for X-Men: Days Of Future Past, and you can listen to it below (from 31.50).

“No, they haven’t [asked me to return]. Someone asked me that the other day and I said no. I know the one that’s coming up shoots this Spring, but I wouldn’t be available anyway. I dont think they have. I was going to meet my manager for dinner later, I was going to ask him about it, but no, I’m sure they would’ve told me, had they approached.”

There was a worry that Halle Berry wouldn't be back as Storm for Bryan Singer's X-Men franchise mash-up X-Men: Days Of Future Past, but it's now been confirmed that she's on board. Alan Cumming's attendance, however, is still up in the air - with rumours of his casting fueled by a Heat Radio interview with the young Professor X himself, James McAvoy.

Answering a softball question about how exciting the X-Men: First Class sequel's castlist is, McAvoy said: "Nick Hoult will be back, Patrick Stewart, Ian McKellan, Halle Berry, Alan Cumming, Peter Dinklage I hear mentioned - I don't know if that's happening - Hugh Jackman..."

You can listen to it for yourself below (the X-Men stuff starts at 4.40) and try to work it out for yourself: is Cumming actually part of the project or is McAvoy just listing some franchise names that occur to him? Or is this a little sneaky reveal from the much-loved mind reader? On one hand, he's in a position where he might know. On the other, he didn't seem sure if Dinklage had signed (which Singer reports he has) so he may be behind the news.

But don't get too excited - ComingSoon.com report that Alan Cumming's definitely not coming back (without any direct quotes, mind), which would make sense considering how much the Goldeneye star hated putting on Kurt Wagner's extensive and time-consuming make-up.

That said, Cumming told ComicBookMovie.com back in December that, at that point, he hadn't received a call about it but was positive. "Someone told me that Nightcrawler doesn’t appear in the story but I don’t know, I think they would have called by now."

"It was funny that film because I really like it and everyone really responded to Nightcrawler and enough time has elapsed that I would like to go back to it. Although then when I did that film it was sort of the start of this spate of superhero and comic books made into films so it felt a little more special then it does now. X2 was a really great film, not just as a comic book film. I think it’s one of the films I’d been in that I think of as really good."

As for Nightcrawler's biological father Azazel (played by Jason Flemyng in First Class), he's definitely not part of the gang this time around.

In other words, everything's very much unconfirmed when it comes to Nightcrawler/Alan Cumming's involvement, and until Fox or Mark Millar or Singer or Cumming himself say anything directly, it's probably best to file this under a massive question mark in your mind.

What is certain, however, is that X-Men: Days of Future Past is set ten years after the events of 2011's X-Men: First Class, and that it's aiming for a July 18, 2014 release. The script comes from First Class's writer/director Matthew Vaughn and X-Men: The Last Stand's Simon Kinberg, and Bryan Singer is coming back to curate this mutant megamix after skipping out on helming The Last Stand.

Just to remind you of how great Nightcrawler is on screen, here's the fantastic X2 scene of Alan Cumming doing this thing at The White House. "BAMF!"