Los Angeles ( CNN ) -- A drug addiction expert who testified that Michael Jackson suffered a `` quite extensive '' drug addiction acknowledged there was no evidence the singer used more painkillers than medically necessary . Dr. Petros Levounis testified Tuesday and Wednesday for AEG Live in its defense of the wrongful death lawsuit filed by Jackson 's mother and children . Lawyers for the concert promoter want to convince jurors that the singer was a secretive addict responsible for his own death from an overdose of the surgical anesthetic propofol . Their executives had no way of knowing the singer was in danger when he was preparing for his comeback concerts in 2009 , they contend . Jackson lawyers contend AEG Live executives are liable because they negligently hired , retained or supervised the doctor who used propofol to treat Jackson 's insomnia as he prepared for his comeback concerts during the last two months of his life . The conclusion that Jackson was dependent on painkillers was not a revelation , considering Jackson himself announced it when he cut his `` Dangerous '' tour short to enter a rehab program in 1993 . `` If he announced it to the world it 's not very private , is it ? '' Jackson lawyer Michael Koskoff asked Levounis . `` At that moment , he was not secretive , '' Levounis replied . Jackson 's drugs of choice were opioids , painkillers given to him by doctors repairing scalp injuries suffered in a fire and during cosmetic procedures to make him look younger , Levounis testified . Labeling Jackson an addict could tarnish the singer 's image among jurors , but its relevance to AEG Live 's liability is questionable . Opioids played no role in Jackson 's death , according to the Los Angeles County coroner . His June 25 , 2009 , death was ruled a result of an overdose of propofol . Dr. Conrad Murray told investigators he infused the singer with propofol for 60 consecutive nights to treat his insomnia so he could rest for rehearsals . The judge would not allow Levounis to testify if he thought Jackson was addicted to propofol . Anesthesiologist : Jackson recruited me to help with insomnia . Levounis said addiction happens when a chemical `` hijacks the pleasure-reward pathways '' in your brain . `` You remain addicted for the rest of your life , '' Levounis testified . `` Michael Jackson 's addiction was quite extensive and I have very little doubt that his pleasure-reward pathways had been hijacked and he suffered from addiction , '' he said . Levounis conceded he saw no evidence that Jackson used painkillers after he left rehab in 1993 until 2001 or between July 2003 and late 2008 . He said it is not inconsistent for an addiction to go into remission . Under cross examination Wednesday morning , Levounis conceded that he never saw evidence that Jackson injected himself with narcotics , ever sought or used illegal drugs such as cocaine , meth or heroin , or abused drugs to produce euphoria or get high . There was also no evidence Jackson used more painkillers than doctors prescribed , he said . Jackson lawyers have never disputed the singer 's drug dependence . In fact , they contend that AEG Live executives , including one who was Jackson 's tour manager when he entered rehab , were negligent for paying a doctor $ 150,000 a month just to treat Jackson . The high salary created a conflict for the debt-ridden Murray , making it difficult for him to say no to Jackson 's demands for drugs . Paul Gongaware , the AEG Live co-CEO who was in charge of Jackson 's 2009 `` This Is It '' tour , was also tour manager for his `` Dangerous '' tour in 1993 . Levounis acknowledged in testimony Wednesday that there was evidence that Gongaware knew about Jackson 's painkiller addiction 15 years before his death . Levounis ' testimony about the dangers of a doctor being too friendly with an addicted patient , which he said Murray was , could help the Jacksons ' case . `` A very close friendship between an addicted patient and a doctor is problematic , '' Levounis testified . `` It makes it much easier for a patient to ask for drugs and it makes it more difficult for a provider to resist . '' The medical records of Murray 's treatment of Jackson between 2006 and 2008 -- when the singer lived in Las Vegas -- showed no painkillers prescribed during seven visits . Murray 's notes did show he treated Jackson 's complaints of insomnia with a sedative in 2008 . Wednesday was the 76th day of testimony in the trial , which is expected to conclude near the end of September .
NEW : Expert finds no evidence Jackson ever took or used illegal drugs . NEW : No evidence Jackson used more drugs than doctors prescribed , expert testifies . Jackson 's mom and children contend that Live is liable in the singer 's death . AEG Live argues it could not have known about Jackson 's drug use .