The Jackson family allegedly believe that a Michael Jackson impersonator was hired for the star to plug his last world tour This Is It.
The double was allegedly used in 2009 at the O2 arena in London at a press conference ahead of the Beat It singer's highly-anticipated tour where Dermot O'Leary shared the announcement with the public.
This is the man the Jackson claim impersonated Michael Jackson (WENN)
According to the Daily Star, the famous family believe that the fake was also used in clips of the King of Pop rehearsing for the summer gig.
The allegations are reportedly in the £26bn lawsuit against the late singer's concert promoters AEG.
Michael's children Prince,16, and Paris,15, along with his mother Katherine reportedly believe the unidentified man was hired to step in place of the star as he was not feeling well.
The family are also claiming that AEG "mishandled" the singer, who died just three weeks before the tour from a fatal dose of anaesthetic.
"In my opinion the man in the clips isn't Michael Jackson," body language expert Bianca Cobb, told the Daily Star.
"The walk is cockier and had more bounce than MJ's typical stride. He tended to walk with his head down," she added.
The family are now said to be appealing for the man to come forward and testify at a Los Angeles court.
"Paris and Prince and their gran believe a fake Michael Jackson was involved. They have hired detectives to track him down," a source told the tabloid.
AEG have denied the claim, while Sony, which released the move This Is It have said that in the footage "every frame is undeniably Michael."