LOS ANGELES , California ( CNN ) -- The Los Angeles Coroner 's chief investigator revisited the office of Michael Jackson 's dermatologist Wednesday , even though the coroner announced last week his `` thorough and comprehensive '' report was completed . Dr. Arnold Klein denied in a CNN interview last month that he had given Jackson dangerous drugs . `` We wanted some additional information , and they provided it , '' Ed Winter said as he emerged 90 minutes after entering Dr. Arnold Klein 's Beverly Hills , California , dermatology clinic . Winter , who also visited Klein 's office on July 14 , said the doctor 's staff and lawyers cooperated with his requests . Garo Ghazarian , one of Klein 's two lawyers on the scene , said the doctor did not meet with Winter . `` They had inquiries born out of information they wanted to corroborate , '' Ghazarian said . Ghazarian said he was added to Klein 's legal team `` to take a look and see if there 's any cause for concern in light of media reports '' that investigators were considering criminal charges against him . `` I have seen no cause for concern on behalf of my client , Dr. Arnold Klein , '' Ghazarian said . The coroner 's office said more than a week ago that a `` thorough and comprehensive '' report into the death of Michael Jackson is complete , but police have requested that the report not be released yet because of the ongoing criminal investigation . The coroner 's office said it would abide by the request that `` the cause and manner of death remain confidential , '' and referred all questions to the Los Angeles Police Department . Winter would not say what prompted the coroner 's office to revisit its conclusions . Jackson 's June 25 death is also the focus of an investigation by Los Angeles police , the state attorney general 's office and the U.S. Drug Enforcement Administration . Klein , who treated Jackson for decades , denied in a CNN interview last month that he had given Jackson dangerous drugs . `` If you took all the pills I gave him in the last year at once , it would n't do anything to you , '' he told CNN 's Larry King . Jackson visited Klein 's office several times in the weeks before his death , including one visit just three days before . Dr. Conrad Murray , Jackson 's personal physician who is under investigation , said in a video posted online Tuesday that he has `` faith the truth will prevail . '' Murray , who was with Jackson when he died , recorded the one-minute video in Houston , Texas , last Wednesday and it posted on YouTube Tuesday , the spokeswoman for his lawyer said . `` I have done all I could do , '' Murray said . `` I told the truth , and I have faith the truth will prevail . '' Watch Conrad Murray say , `` Do n't worry ... I 'll be fine '' » . Murray , a cardiologist , owned and operated two medical clinics -- in Las Vegas , Nevada , and Houston -- but he took a full-time job as Jackson 's personal doctor in May , as the pop singer prepared for his comeback concerts scheduled to start in July . Investigators have searched Murray 's home and clinics for evidence related to the anesthetic propofol , according to documents filed in court . A source close to the investigation told CNN it 's believed Murray administered the drug , also known by the brand name Diprivan , to Jackson within 24 hours of his death . Ed Chernoff , Murray 's lawyer , said it was only after Murray moved to Los Angeles in May 2009 that `` he realized that Michael Jackson had some very unusual problems . '' Chernoff , in comments published in the Los Angeles Times and confirmed by his spokeswoman , said that when Murray took the job , his client did not know what drugs Jackson might have been taking or whether he was addicted . Murray did not conduct drug tests on Jackson and had no way of knowing , other than from Jackson 's words , if he was taking other drugs , Chernoff 's spokeswoman , Miranda Sevcik , told CNN . One of the warrants used in searches of Murray 's home and clinics implied that police suspect Jackson was a drug addict . Chernoff has refused to confirm or deny whether Murray administered propofol to Jackson , although he denied `` unequivocally '' that Murray gave Jackson painkillers . A former prosecutor who has also defended doctors in medical malpractice cases involving anesthesia said prosecutors would face `` a very , very severe uphill battle '' when charging a doctor with manslaughter . `` You have to prove gross recklessness in the prescription of drugs , '' Paul Callan told CNN . `` That 's really hard with a doctor because doctors are always prescribing drugs ; patients occasionally die from them . That 's not criminal conduct . But here , you have to show that this doctor should 've known Jackson was an addict and that he could 've died from these drugs . ''
` ` We wanted some additional information , '' chief investigator Ed Winter said . He had said it completed ` ` thorough '' report into Michael Jackson 's death . Winter did not say what prompted the second report or its conclusion . ' Arnold Klein , Jackson 's psychiatrist , has been giving him dangerous drugs .