Perez Hilton's celebrity gossip blog claims that the duo are about to be named by Fox as the show's hosts - taking over the baton from Britain's Steve Jones.
Lopez was apparently considered for the role before the show launched, but lost out to Jones. However US audiences have failed to warm to the Welshman as much as producers had hoped.
Simon Cowell has previously acknowledged that Khloe K was in the frame for the job - and has also said that a boy-girl pairing was being sought.
Meanwhile Kelly Osbourne has distanced herself from speculation that she might get the job.
Speaking to Alan Carr, she said: "Everybody keeps talking about it. I have not spoken to Simon (Cowell). Of course if he wanted me it would be such an honour but there are probably better people than me."
The new series of The X Factor USA has got off to a shaky start in the ratings.
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