MALIBU, Calif. - Attorneys for Floyd Landis began trying to paint a picture yesterday of incompetence at the French lab where the cyclist's urine was tested.

Using computer logs from the lab, Landis' attorneys tried to prove lab workers manipulated the calibration of the machine that performed tests on the cyclist's backup samples - and claimed a U.S. Anti-Doping Agency scientist tried to prevent the Landis camp from seeing the logs.

"Because without these log files, we wouldn't know about the data that was deleted," Landis attorney Maurice Suh said.

Suh showed instances where calibration tests were performed, then rerun, and the first records of those tests were erased by the new results.

Landis is accused of using banned synthetic testosterone during his Tour de France victory last year. The Lancaster County native appeared for the second straight day at his arbitration hearing in a yellow tie, one that matches the color of the jersey he won.

A three-man panel will decide whether to uphold his positive doping test. If it does, Landis could face a two-year ban from cycling and become the first person in the 104-year history of the race to have his title stripped.

During the Tour, Landis was tested eight times. Of those, only one tested positive. But last month, USADA asked that the backup "B" samples of his seven negative tests be subjected to carbon-isotope ratio testing to look for synthetic testosterone. Four of those seven returned with "abnormal testosterone profiles," and the Landis camp is trying to prove it is a result of mishandled tests.

The carbon-isotope tests were not done during the Tour because those samples did not exceed the allowed 4-1 ratio of testosterone to epitestosterone.

Landis' attorneys have fought having these tests done. After losing on that issue, they're now going after the tests' accuracy.

Later in the morning, Cynthia Mongongu, an analyst at the French lab who worked on Landis' positive sample, took the stand. Mongongu speaks French, and with communication nearly impossible among her, the translator and the USADA lawyers who were questioning her, testimony was delayed nearly two hours to try to improve the situation.

The nine-day hearing began Monday with opening statements from both attorneys.

"Make no mistake about it," Suh said, "this case is an utter disaster."

Richard Young, the lead attorney presenting USADA's case, said in his opening statement that despite the publicity, this was simply another in a long list of cases USADA handles - one in which the cold, hard scientific data would prove an athlete had used synthetic testosterone.

"There's nothing unique about what the panel has to decide," Young said. "It's one of dozens of cases in which a high testosterone-to-epitestosterone ratio is confirmed by" a different, more sensitive test.