Did Iran really produce a "superdollar"???

I have read in a couple of articles how the Iranian Government were able to produce a forgery of a 100 or 1 dollar bill (I forget which one exactly) so sophisticated and skillfully done it even couldn’t be detected by the agents at the US Treasury.

It was mentioned in a show dedicated to forgeries on the History Channel and also in the film Rush Hour 2, though I’m not sure how realistic thier slant on it was.

So the question remains, how the heck did these guys come up with the “superbill”? And is it in circulation now?