Computer Forensic Examiner -- Stephen Marx Testifies
Updated 10/05/11 at 09:55 AM

Dramatic testimony today ... suggesting there were strong signs Michael Jackson's health was deteriorating days before his death.

Stephen Marx -- the forensic expert who analyzed Dr. Conrad Murray's iPhone -- uncovered a voicemail message in which Michael Jackson's manager referred to "anepisode" MJ had five days before he died.

Prosecutors played the June 20th message during Marx's testimony -- in which Michael's manager Frank DiLeo says, "I'm sure you're aware [Michael] had an episodelast night."

Frank clearly believed Michael had a drug problem, claiming, "He's sick. I think you need to get a blood test on him. We gotta see what he's doing."

You'll recall ... Kenny Ortega and others talked about MIchael's heath problems during rehearsal on June 19, 2009, which triggered a confrontation between Ortega and Murray at MJ's house the next day.