Pierre Bordry told The Associated Press that French judge Thomas Cassuto is seeking to question Landis about computer hacking dating back to September 2006 at the Chatenay-Malabry lab. Months earlier, the laboratory near Paris had uncovered abnormally elevated testosterone levels in Landis' samples collected in the run-up to his 2006 Tour de France victory.
Landis was stripped of his title and banned for two years.
The American cyclist unsuccessfully challenged the drug test results before an arbitration hearing in California claiming that computer files were mishandled and erased.
"Landis used the hacked files for his defense, that's how we discovered the whole scheme," Bordry said. "He wanted to show that the lab made mistakes in the handling of the tests." Landis did not immediately respond to a phone call and e-mail seeking comment.
The French judge, who is based in the Paris suburb of Nanterre, issued the warrant Jan. 28 because Landis did not respond to a summons in November, Bordry said. The Nanterre prosecutor's office confirmed the warrant had been issued.
"Apparently the judge traced the case back to the beginning," Bordry said. "I can't say I'm happy with this news because I would have preferred there was no Landis case."
Bordry added that Cassuto also issued an international warrant for Arnie Baker, a retired doctor and longtime Landis coach and adviser.
After discovering the hacking, the French lab upgraded security to protect its computer systems.
Landis' urine samples were tested at the lab and found to contain elevated testosterone-to-epitestosterone levels, less than a week after he won the Tour de France.
On July 20, 2006, Landis started the 17th stage of the Tour more than 8 minutes behind leader Oscar Pereiro after losing the yellow jersey to the Spaniard the previous day. The American produced an amazing ride during the mountain stage to cut Pereiro's lead to 30 seconds before taking the title.
Landis' samples taken after that stage revealed a testosterone/epitestosterone ratio of 11:1. The limit is 4:1.
The Chatenay-Malabry lab is accredited by the International Olympic Committee and World Anti-Doping Agency. It helped develop tests for the endurance-enhancing drug EPO.
Landis returned to competition at the Tour of California last year. He recently competed in a minor race staged in New Zealand.