Los Angeles (CNN) -- Michael Jackson traveled with what amounted to a mini-clinic and an anesthesiologist who used a surgical anesthetic to put the singer to sleep after shows during his "HIStory" tour, sources close to Jackson told CNN just days after his death.
But Paul Gongaware testified Friday that he never saw indications Jackson used drugs or traveled with a doctor when he managed that tour in 1996 and 1997.
What Gongaware knew -- or didn't know -- about Jackson's drug use is a key issue as the Jackson wrongful death trial enters its sixth week Monday in Los Angeles.
The co-CEO of AEG Live -- the concert promotion company being sued by Jackson's mother and children -- returns for a fifth day of testimony Monday.
The Jackson family contends AEG Live is liable in Jackson's 2009 death because it negligently hired, retained or supervised Dr. Conrad Murray, who was convicted of involuntary manslaughter.
Gongaware was the top producer of Jackson's comeback concerts when the singer died of an overdose of the surgical anesthetic propofol. It was Gongaware who negotiated the deal to pay Dr. Murray $150,000 a month to be Jackson's physician for the "This Is It" tour.
Jackson lawyers argue that Gongaware should have known the hazards of hiring the doctor because of his personal experience with Jackson -- and his work with other artists, including on Elvis Presley's last tour.
AEG Live lawyers contend their executives had no way of knowing that Murray was using propofol to treat Jackson's insomnia because the singer was very good at keeping his "deepest, darkest secret."
"AEG knew nothing about this decade-long propofol use," AEG Live lawyer Marvin Putnam said in his opening statements. "They were a concert promoter. How could they know?"
Gongaware, under questioning by his own lawyer Friday, testified that he only became aware that Jackson was addicted to painkillers when the singer made a public announcement after his "Dangerous" tour abruptly ended so he could enter rehab in 1993.
He was a manager for the "Dangerous" tour, but only handled logistics and didn't travel with Jackson then, he said.
His job on the second half of the "HIStory" tour, however, carried more responsibilities and he worked closely with Jackson, he said.
Gongaware testified that he saw "no indication at all" that Jackson was using drugs during that tour. "I would be certain to notice it if that was the case."
Did Jackson have a doctor treating him during the "HIStory" tour, his lawyer asked.
"Not that I know of," he answered.
In fact, Jackson was "sensational" on stage, performing 10 to 12 shows a month, he said. Unlike in the "Dangerous" tour, he never canceled a show because of his health.
"He only missed one," he said. "That was when Princess Diana died. He heard about the accident, went to bed, woke up, found she passed away and it affected him deeply."
But an interview that Jackson gave to Barbara Walters weeks after Diana's death could help Jackson lawyers refute Gongaware's claim that no doctor traveled with the singer during the tour.
Walters asked Jackson about how he learned the news that his friend, the princess, had died.
"I woke up and my doctor gave me the news, and I fell back down in grief and I started to cry," Jackson said. "That's why the inner pain, the pain in my stomach and in my chest, so I said 'I cannot handle this. It's too much.'"
Jackson's statement that a doctor was at his bedside when he woke up the day of a scheduled "HIStory" show in Belgium is not the only evidence he did have a physician on the tour.
Dr. Neil Ratner, an anesthesiologist from New York, has acknowledged that he traveled with Jackson during part of the tour. He was at Munich, Germany, in July 1997 when a stage collapsed and Jackson suffered a back injury. It was two months before Diana's death.
Dr. Ratner declined to talk about his treatment of Jackson when CNN's Dr. Sanjay Gupta confronted him outside his Woodstock, New York, home in July 2009, although he did confirm that Jackson had trouble sleeping.
"It's really something I don't want to talk about right now," he told Dr. Gupta.
A source who was close to Michael Jackson told Gupta in 2009 that when Jackson had trouble sleeping that Dr. Ratner helped "take him down" and "bring him back up."
Ratner, who was convicted of insurance fraud and stripped of his license to practice medicine for three years in 2002, is on the witness list for the trial and has been questioned in a deposition by each side.
Debbie Rowe -- Jackson's former wife and the mother of his two oldest children -- will testify that she assisted in administering propofol to Jackson in the 1990s when she was a nurse, AEG Live's Putnam said on the opening day of the trial.
"She saw several doctors put Mr. Jackson to sleep in hotel rooms while on tour," Putnam said, including in Munich, London, Paris.
But Gongaware and others did not know, he said.
"The truth is Mr. Jackson fooled everyone," Putnam said about Jackson's propofol use. "He kept those who might have helped him at a distance and no one knew his deepest, darkest secret."
Jackson's ability to keep his private side private meant AEG executives could not see any red flags warning of Jackson's destruction, Putnam said.
"They didn't see this coming," he said. "They had no idea."
Putnam said Jackson family members -- including Janet and her famous siblings -- will testify about their failed attempts at intervention and their lack of knowledge about what was happening.
"If they didn't know what was going on, how could someone else think there was even a problem," he said.
But Jackson lawyers will argue that Gongaware, who closely watched expenses on the "HIStory" tour because it was losing money at one point, would have noticed spending on hotel rooms and fees for a doctor traveling with the tour.