BBC SPORT | Special Events | 2001 | Tour de France

"As soon as trials come out, it seems not to be difficult to find out what is going on and steal the odd vial or two."

Michelle Verroken, head of anti-doping at Sport England believes some team doctors should shoulder some of the blame.

"There is no doubt some kind of medical collusion. It is not back-street," she said.

"Those who supply should receive an equal or greater sanction."

The Tour begins under the shadow of the scandals to hit this year's Giro d'Italia when 200 Italian drug squad officers raided competitors' rooms in San Remo.

The Tour also has its own skeleton, the Festina scandal of the 1998 race when raids on hotel rooms used by 20 teams discovered a witch's brew of chemicals, along with syringes.

The trial which followed exposed endemic doping and to avoid a repeat, Tour officials have proposing a 10-step programme.

Jan Ullrich has had to give up his mother's cakes

This will include daily checks on 10 cyclists, as well as the first three in the overall rankings.

Even favourite Lance Armstrong, winner of the last two Tours, goes into the race under a cloud.

The results from the US Postal team's drug tests from last year's Tour, including Armstrong's, have been delayed for at least another month.

Tour officials have allowed US Postal to line up for the start.

Armstrong's recovery from testicular cancer is a well-documented triumph of human spirit over adversity.

After completing back-to-back victories last year, the Texan was subjected to suspicion.

But Armstrong has been tested more than any other cyclist in recent years and passed each time.

Addiction

The biggest threat to Armstrong comes from Telekom rider Jan Ullrich who admits to a past addiction - to his mother's cakes.

After finishing second on his Tour debut in 1996 and winnig the following year, he was tipped to dominate the sport.

But a combination of bad luck, poor fitness and the emergence of Armstrong combined to earn Ullrich the tag of a One-Tour Wonder.

Santiago Botero's province is the mountains

A ride in the Giro d'Italia has him looking fitter than at any time since 1997.

Colombian Santiago Botero carries the burden of restoring his nation's sporting reputation.

With the Copa America postponed, and their government struggling to win a drugs war, last year's King of the Mountains will provide a welcome distraction for many in Colombia.

The mountains are Botero's domain and if Armstrong and Ulrich falter, the door could open for him.