Given [artist id="1102"]Michael Jackson[/artist]'s long, twisted legal history, it's almost expected that his upcoming [article id="1606985"]50-date residency at the O2 Arena in London[/article] would not go off without lawyers getting involved. The latest potential roadblock appears serious, though.

Reuters reported that music promotions company AllGood Entertainment is planning to sue Jackson, claiming that he signed a contract last year that prevents him from performing live until July 2010.

The New Jersey-based company says that it signed an agreement in November with Jackson's manager, Frank DiLeo, that committed the singer to performing in a Jackson family reunion tour -- which was also to include [artist id="1090"]Janet Jackson[/artist] -- slated to launch in July 2010. Under that agreement, Jackson is reportedly not allowed to perform live until the reunion tour, an 18-month blackout that coincides with his planned solo shows in London.

AllGood has reportedly sent a cease-and-desist letter to DiLeo and AEG Live, the promoter of the London shows, which have been billed as the troubled singer's comeback to live performance after 12 years off the touring stage. While a spokesperson for AEG could not be reached for comment at press time, an unnamed representative reportedly acknowledged to Reuters that the company had been contacted, but called AllGood's claims "meaningless." MTV News could not reach DiLeo for comment at press time.

According to TMZ, Jackson is claiming he never signed on for the family tour. But TMZ says that his manager did sign the agreement on his behalf, and the law allows for an agent to sign on behalf of his client.

AllGood's managing partner told Reuters that after failing to reach a negotiated agreement with DiLeo, the company will file a lawsuit by week's end. AllGood's plan is for a one-off Jackson family show at Texas Stadium on July 3, 2010, that would be available on pay-per-view and broadcast over the Internet.

As the legal mess untangles itself, Jackson has reportedly been rehearsing for the shows six hours a day, four days a week at a warehouse space near the Burbank airport in Los Angeles. With a group of 10 dancers, renowned choreographer/director Kenny Ortega ("High School Musical") is overseeing what the Los Angeles Times reported is a $20 million production with as many as 22 different sets. Promoters promise it will be the biggest, most technologically advanced, and most expensive, arena show in history.

Ortega also helped choreograph Jackson's Dangerous and HIStory tours and is directing and designing the London shows along with younger choreographers such as Todd Sams (Usher) and Rich & Tone Talauega (Chris Brown), who were on site for last month's auditions. The two-day casting call resulted in 700 dancers turning out, who were then whittled down to two female and eight male dancers.