Floyd Landis is sticking to his story despite new evidence.
He told National Public Radio on Friday that elevated levels of testosterone in his body were naturally produced, and he expects his "B Sample" to show similar levels.
"The problem is not a problem with the test as far as I know," he told NPR. "The problem is that, at times, from the way it's been explained to me, there are variations in the ratio [of naturally-produced hormones]. And for some reason, in some individuals there are numbers which don't fit the criteria which they claim to be natural."
He said he plans "to ask for an endocrinological review of my body to prove that there are times during the day or at some points that if I were tested I would be shown to be out of the 4:1 ratio, albeit from a natural cause. Explaining that, I can't. I'm waiting for the experts to do that."
But a big problem for that argument appeared on the New York Times Web site last night. Sources tell the Times some of the testosterone detected in Landis's urine is synthetic, which would refute his argument that it was made naturally by his body.
Landis has yet to respond.
His B Sample results are expected Saturday.