Paris, Oct 14 (DPA) Organizers of the Tour de France presented Wednesday the course for next year’s edition of the race as doping suspicions once again plagued the world’s most prestigious cycling event.

The 2010 Tour de France will start on July 3 in the Dutch port of Rotterdam with an 8- km prologue, the fifth time in its history the race has opened in the Netherlands. It will end on July 25 on the Champs Elysees in Paris.

The 3,590-km course favours strong climbers, such as last year’s winner Alberto Contador of Spain and seven-time champ Lance Armstrong. It includes 23 mountains, two more than last year, and three mountaintop finishes.

The last of those finishes, atop the legendary Col du Tourmalet in the Pyrenees, July 22, is likely be the decisive stage in the race.

As part of the celebrations marking the 100th anniversary of the first time the Tour de France passed through the Pyrenees, the riders will be climbing the Col du Tourmalet twice, during the 16th stage and at the conclusion of the 17th.

The presentation took place the day after French media reported that the Paris public prosecutor’s office has opened a preliminary investigation into doping after the discovery of a substantial amount of suspicious material during the running of this year’s Tour.

Several teams are targeted by the investigation, but most of the attention has been focused on the Kazakh team Astana, which included 2009 Tour winner Alberto Contador and seven-time Tour champion Lance Armstrong, who finished third this year.

Agents from the Office Against Damage to the Environment and Public Health reportedly recovered “hundreds of syringes” and “perfusion material” during the running of the race. These are currently being analyzed.

The news of the investigation came a little more than one week after the French Anti-Doping Agency leaked a report that accused inspectors from the world’s ruling body, the Union of International Cycling (UCI), of having accorded Astana preferential treatment during the Tour.