Den stora skvallertråden om Michael Jackson [Död 090625]

The wound seen in the photos, which were taken in 2002, could have been a result of contact with highly caustic, acidic fluid that would burn the skin and cause it to turn black, Jaliman said.

Reports of prescription drug abuse had dogged Jackson for much of his career.

Marc Schaffel, a long-time adviser to Jackson, said the star was dangerously addicted to the painkiller Demerol, as well as to a cocktail of other opioid drugs, such as Oxycontin.

"It's Michael who wanted the drugs -- Michael who was doing it. Nobody could stop Michael except Michael himself," Schaffel said. "If, in fact, the family was able to spend time with him over the last couple years, they would know he was on drugs."

But Jaliman said that from the photos, it appears that Jackson used a depigmentating agent on certain parts of his body to even out his skin tone. "When people have vitiligo and they have such uneven discoloration, oftentimes they take a dipigmenting agent, which is a cream, and you can actually destroy the very dark color cells that you have and then you make your skin very, very white," Jaliman said.

"If you look at his hands, they are totally depigmented. And in vitiligo, you would never see that. So I would start to think that he might have used a depigmenting agent," she said.