In this March 5, 2009 ,file photo, U.S. singer Michael Jackson announces that he is set to play a series of comeback concerts at the London O2 Arena in July, which he announced at a press conference at the London O2 Arena. Attorneys for Katherine Jackson argued for a new trial before a California appeals court on Thursday Jan. 22, 2015, in her case against concert promoter AEG Live LLC, who she claims should be held liable for her son's death in 2009. (AP Photo/Joel Ryan, File)

LOS ANGELES (AP) — A California appellate court has heard arguments on behalf of Michael Jackson’s mother for a new trial in her lawsuit against concert giant AEG Live LLC.

Attorneys for Katherine Jackson told a three justice panel of the 2nd District Court of Appeal in Los Angeles that a new trial should be ordered because jurors who decided a nearly six-month trial in AEG’s favor last year were given an improper verdict form.

Katherine Jackson sued AEG, the promoters of her son’s ill-fated “This Is It” comeback concerts, claiming they were responsible for her son’s 2009 death because they hired the doctor who administered a fatal dose of anesthetic.

AEG’s lawyers however argue that the Jackson family matriarch’s attorneys sought the exact question jurors used to decide the case in AEG’s favor.