4:45 PM PT -- The duet isn't going to happen, after all. Sources connected to the deal tell us Whitney's estate decided to pull the plug once they saw the finished product 2 days ago.
We're told they weren't satisfied because the hologram simply "didn't look like Whitney." Producers and the estate reps all agreed Christina was flawless, but until technology can do the same for Whitney ... no deal.It appears the Christina Aguilera-Whitney Houston duet rumors are true -- what looks very much like video of the performance just popped up on the Internet ... briefly.
It was supposed to be a surprise for Monday's season finale of the "The Voice" -- though there's been a ton of buzz about it, so the surprise was already kinda blown. It's unclear who got the footage or how it ended up on a Facebook page ... but it's already been taken down.
We've seen the whole thing, and we won't blow the whole secret ... but it appears Christina will sing a medley of Whitney's hits with the hologram.
'Voice' reps haven't gotten back to us yet about whether the footage is legit.