The Web site claims that Jackson's manager, Frank Dileo, signed a deal in 2008, promising the superstar entertainer would hit the road with his brothers and Janet Jackson.
The deal reportedly stopped Jackson from setting up any other concert deals for a year-and-a-half.
Now, AllGood Entertainment, which had been putting together the family trek, are claiming Jackson signed the London deal before the other contract was up, violating the original contract, according to TMZ.
The Web site claims Jackson didn't himself sign up for the family tour, however his manager did, TMZ reported.
Reps for the London shows were not immediately available for comment.