MALIBU, Calif. — At last, a chance for some compelling testimony at the Floyd Landis arbitration hearing.

The U.S. Anti-Doping Agency planned to call three-time Tour de France winner Greg LeMond to the witness stand Thursday.

LeMond has recently been outspoken in his criticism of Lance Armstrong, saying he doubts Armstrong rode clean during his seven-year reign as champion in cycling's biggest race. USADA's witness list says LeMond "will testify regarding conversations he had with Respondent and related events."

LeMond's appearance, expected in the afternoon, could be a dramatic change after two days of slow and difficult testimony from French-speaking analyst Cynthia Mongongu, who tested some of Landis' samples at the lab outside Paris.

Her most interesting moment Wednesday came when she testified that she taped a do-not-cross line across the floor of her workspace to keep Landis' observers from interfering last month with tests of his backup "B" urine samples.

She was responding to questions about a written statement she signed last month in which she stated she was "accosted" by one of Landis' experts. She testified it was not a physical confrontation.

"I needed to be able to concentrate on my work," she said in French, her testimony relayed by a translator.

Landis is accused of using banned synthetic testosterone during his 2006 Tour victory.

Much of the testimony Wednesday was about the backup "B" samples of Landis' seven negative tests that were, at USADA's request, subjected to carbon-isotope ratio testing last month to look for synthetic testosterone. Four of those seven returned "abnormal testosterone profiles," and the Landis camp is trying to prove that's a result of mishandled tests.

A three-man arbitration panel hearing nine days of testimony will decide whether to uphold his positive doping test after Stage 17 of last year's Tour. If it does, Landis could face a two-year ban from cycling and become the first person in the 104-year history of the Tour to have his title stripped.

Most hearings like this are wrapped up in four or five days, but this one's unique because it's the first to be held in public. Further complicating matters is the translation, which slows things down immensely.

After lunch, Mongongu's testimony came to a halt when she told attorneys she needed a more detailed graph of results from a test used to calibrate the machine that analyzed Landis' urine. Without it, she said she couldn't answer questions about whether the test gave a truly accurate measurement.