Sharon Osbourne has been added to the prosecution's all-star witness list in the Michael Jackson wrongful death trial after the rock matriarch suggested she had information that could prove useful for the King of Pop's mother as she sues concert promoters AEG Live.

Katherine Jackson filed suit against the promoters behind the Thriller hitmaker's doomed This Is It comeback gigs, claiming they were negligent in ignoring life-threatening health concerns and holding them responsible for hiring Conrad Murray, the medic who was convicted of involuntary manslaughter for causing the superstar's death in 2009.

Pre-trial proceedings began in a Los Angeles court on Tuesday (02Apr13) and the witness list submitted by Jackson's lawyers included celebrity friends such as Diana Ross, producer Quincy Jones, director Spike Lee and Michael's ex-wife Lisa Marie Presley.

Ozzy Osbourne's manager wife was also added to the list on Wednesday (03Apr13) after speaking out during Tuesday's (02Apr13) episode of her U.S. chat show The Talk.

She 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."

Her comments caught the attention of Jackson's lawyers and they have since been in touch about possibly calling her to take the stand.

Returning to The Talk on Thursday (04Apr13), she reveals, "I have been contacted by the Jackson family lawyer... and I will do my duty of telling the truth and now I have been contacted by lawyers I can't say anything else other than that."

Katherine Jackson is reportedly seeking more than $40 billion from AEG Live executives for loss of future earnings and other damages.