Rock matriarch Sharon Osbourne has been subpoenaed to testify in the Michael Jackson wrongful death trial. Opening statements in the battle between the King of Pop's mother, Katherine Jackson, and concert promoters AEG Live began in Los Angeles County Superior Court on Monday (29Apr13) and on Tuesday (30Apr13), Ozzy Osbourne's wife was served with papers demanding her attendance to serve as a witness for the prosecution. The TV personality had previously been named as a potential witness after confessing that she may have evidence to support Katherine's claim that promoters were negligent in ignoring life-threatening health concerns while organising the Thriller hitmaker's doomed This Is It comeback gigs. Speaking out during an episode of her U.S. chat show The Talk in early April (13), Osbourne said, "There were certain people that worked at that company (AEG Live) that knew that Michael Jackson was not well and didn't care because it was business. And, at the end of the day, whether he performed or he didn't, they would still make money, and I've had conversations with certain people at that company who have said exactly that to me. "If they would like me to go to court, the Jackson family, I will stand up and tell you who said that to me." Osbourne was served with court papers shortly before filming began on Tuesday's (30Apr13) episode of The Talk, and she has no problem with the order. She explains, "I was like, what do you do (after being served)? You do your duty. Somebody asks you to come to court, you are subpoenaed and you do your duty." Katherine Jackson is reportedly seeking more than $40 billion from AEG Live executives for loss of future earnings and other damages. She also wants the concert bosses to be held responsible for hiring Conrad Murray, the medic who was convicted of involuntary manslaughter for causing the superstar's death in 2009.