Douglas said Alvarez was with Jackson and his doctor Conrad Murray in the pop star's bedroom in the critical moments before paramedics arrived, the Los Angeles Times quoted him as saying.

He said Alvarez could provide useful information that would confirm or contradict Dr Murray's version of events and provide independent insight into what transpired.

In their report Monday, police said Murray gave Jackson the powerful anesthetic Propofol at 10.40 a.m., watched him for 10 minutes and went to the restroom for two minutes.

When he returned at about 11 a.m., Murray found that Jackson had stopped breathing.

Police said three phone calls of 47 minutes were made from Murray's phone, beginning at 11.18 a.m. The police (911) were called only at 12.22 p.m.

The 'King of Pop' died just days before he was to begin his comeback concert tour 'This Is It'.