LOS ANGELES, California (CNN) -- When Michael Jackson collapsed at his rented mansion last month, the singer's arms were riddled with marks and their veins had collapsed -- both characteristics found in intravenous drug users, sources told CNN on Tuesday.



A source says Michael Jackson had "paper white skin. As white as a white T-shirt."



The revelations add to the speculation that prescription drugs played a part in Jackson's death on June 25. The exact cause is pending toxicology results that aren't due for at least another week.



A source involved with the investigation into Jackson's death told CNN that Jackson had "numerous track marks" on his arms -- and that those marks "could certainly be consistent with the regular IV use of a drug, like Diprivan."



The sources did not want to be identified because the investigation is ongoing.



The source said investigators found numerous bottles of prescription drugs in the singer's $100,000-a-month rented mansion in Holmby Hills, but he would not confirm whether Diprivan was among them.  Watch what sources say on condition of Jackson's body »



He also cautioned that it was too soon to say whether an intravenous drip of Diprivan caused the track marks. Some appeared fresh; others older, he said. The new ones could have resulted from the IVs that paramedics used when they tried to revive Jackson after he was found unconscious.



Another source with knowledge of the case said Jackson's veins were collapsed in both arms, suggesting frequent intravenous drug use.



The first source said Jackson's body was "lily white from head to toe," perhaps the result of vitiligo -- a condition that causes the skin to lose melanin and produce slowly enlarging white patches.



The second source said Jackson had "paper white skin. As white as a white T-shirt."



The singer also did not have any hair -- a lingering effect, possibly, of an accident in 1984 when Jackson suffered burns to his scalp while shooting a commercial for Pepsi.



Also, said the second source, Jackson was emaciated -- despite the vigor he's seen displaying in a taped rehearsal clip shot two nights before his death.



The drug Diprivan, known by its generic name Propofol, is administered intravenously in operating rooms as a general anesthetic.



Last week, a nutritionist -- Cherilyn Lee -- said Jackson pleaded for the drug despite being told of its harmful effects, because he had difficulty falling asleep.



Sources close to Jackson told CNN that the insomniac singer traveled with an anesthesiologist who would "take him down" at night and "bring him back up" during a world tour in the mid-'90s.



The California state attorney general's office is helping the Los Angeles Police Department in Jackson's death investigation. The office confirmed it is investigating some doctors who treated Jackson over the years.



The U.S. Drug Enforcement Administration is also looking into the role of drugs.



Los Angeles police have interviewed Jackson's cardiologist, Dr. Conrad Murray. They impounded Murray's car, saying it might contain evidence, possibly prescription medications. Police did not say whether they found anything.



Through his lawyers, Murray has released several statements, saying he would not be commenting until the toxicology results from Jackson's autopsy are released.



Dr. Neil Ratner, the anesthesiologist who accompanied Jackson during the HIStory tour in the mid-'90s, also refused to comment, although he acknowledged Jackson suffered from a sleep disorder.



CNN's Susan Chun contributed to this report.
How many marks were on his arms exactly? what cuased his death? Who is the second source being referred to? Who is handling the toxicology tests?
"numerous track marks" exact cause is pending toxicology results "paper white skin. As white as a white T-shirt." The California state attorney general's office is helping the Los Angeles Police Department in Jackson's death investigation.
question: How many marks were on his arms exactly?, answer: "numerous track marks" | question: what cuased his death?, answer: exact cause is pending toxicology results | question: Who is the second source being referred to?, answer: "paper white skin. As white as a white T-shirt." | question: Who is handling the toxicology tests?, answer: The California state attorney general's office is helping the Los Angeles Police Department in Jackson's death investigation.