Their lawyer, Mark Geragos, says he will refer the case to prosecutors for possible criminal charges against the insurer, Cigna HealthCare.

"All of the doctors there unanimously agreed that she needed and should have that liver transplant. And the only entity, if you will, who said no to that in the middle of that medical decision, was some piece of garbage who decided that making a couple of dollars, or saving them a couple of dollars, was worth more than the 65% chance over six months that she would survive," said Geragos.

"The only reason they approved it is because we had organized a protest in front of Cigna's corporate headquarters& and in the face of public pressure, they did it," he said.

By the time the approval came through Nataline had been on the liver transplant list for two weeks and her condition had deteriorated so badly that it was too late to have the procedure.

"I believe, the corporation knew, powers that be knew, that at that point approving the liver transplant was a 'gimme' because her condition deteriorated to the point where she couldn't receive the liver&she didn't have any chance of either, one, getting a liver or, number two, actually being able to receive it," he says.

Nataline, who was fighting leukemia, developed liver failure after complications from a bone marrow transplant she received from her brother last month.

Despite her already fragile health, Geragos says, "all of the doctors at the University of California Medical Center unanimously agreed that she needed and should have that liver transplant."

More than 6,000 liver transplants are performed in the United States every year, making it one of the most common organ transplants, according to the United Network for Organ Sharing.