This is just a rumor ... but what a rumor it is!

Sources are putting together various reports to determine if Michael Jackson will appear on American Idol later this season.

Realitytvmagazine.com reports that "several signs" point to the possibility that Jackson will have his own Idol theme-week, and might even "mentor" the impressionable young talent on the show.

Why all the Jackson buzz?

First of all, American Idol producers have hinted for weeks at a "big event show" during this season. Also, reports have swirled that Jackson has turned to Idol creator Simon Fuller to help revive his sagging career, perhaps involving a comeback show in Las Vegas.

Finally, in a recent conference call, executive producer Nigel Lythgoe explained the show's impenetrable wall of silence around contestants, and used Jackson as an example, saying they wouldn't want it to "slip out with somebody telling their mom that Michael Jackson is coming."

Would a savvy operator like Lythgoe really let such a big scoop just slip? Reps for the show had no comment. A rep for Michael Jackson could not immediately be reached.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.