"The French sports daily L'Equipe reported Tuesday that six urine
samples that Armstrong had provided during his first Tour de France
victory, in 1999, had tested positive for the red blood cell booster
EPO.

Armstrong questions the validity of testing samples frozen six years
ago, how those samples were handled since, and how he could be expected
to defend himself when the only confirming evidence -- the 'A' sample
used for the 1999 tests -- no longer exists."

http://www.nytimes.com/2005/08/26/sports/othersports/26cycling.html