Katherine Jackson is now the legal guardian of Jackson's three children. Photo: Reuters

Michael Jackson, shown in 1997, was said to be taking powerful anaesthetics as a sleeping aid. Photo: BBC News

Katherine Jackson and his three children say AEG Live should be held liable for Jackson's death in 2009.

The promoters say they did no wrong and could not have foreseen Jackson's death on the eve of his comeback tour.

Millions of dollars are at stake in the trial, which could last up to 90 days.

Brian Panish, who represents Jackson's relatives, told a court in Los Angeles that AEG Live was the only party that maintained it was unaware of Jackson's addiction to prescription drugs.

'Ultimate price'

"Over the years Michael's family and people who knew him believed he had a problem with prescription medication," Mr Panish told a jury of six men and six women.

"His stirring voice, his musical genius, his creativity and his generosity and his huge heart was extinguished forever," he said, adding that jurors would have to decide who was responsible for the star's death.

But AEG Live's lawyer Marvin Putnam said Jackson's closely guarded private life left the promoters in the dark about his drug dependence.

"The truth is, Michael Jackson fooled everyone," Mr Putnam said. "He made sure that no-one, nobody, knew his deepest darkest secrets."

The case, which is expected to focus on the last months of Jackson's life, his financial history and his overall health, could feature testimony from his children.

It is also reported that stars such as singer Diana Ross, director Spike Lee and music producer Quincy Jones may take the stand.

The trial is expected to focus on Conrad Murray, the former cardiologist who was convicted of involuntary manslaughter in 2011 for administering a combination of sedatives and the anaesthetic propofol that killed Jackson.

The Jackson family claims in its suit, filed in 2010, that AEG Live had not properly investigated Murray's background before he was hired to serve as Jackson's personal physician.

Murray was to be paid $150,000 a month during the This Is It concert series, but Jackson died before the tour began.

Murray is in prison, appealing against his conviction.

Fragile health

AEG Live is expected to argue that Jackson had selected Murray to be his personal doctor, and that Murray was not officially an AEG Live employee.

But his family are expected to argue the concert promoters put pressure on Murray to get Jackson ready for the gruelling tour schedule despite the pop icon's fragile health.

Famous members of Jackson's family, including his sister Janet, are also expected to attend the trial.