Cycling: Boonen trial decision set for Feb 3
Boonen tested positive for the recreational drug in an out-of-competition test in May last year.
Boonen, a former world champion and winner of such prestigious races as Paris-Roubaix and the Tour of Flanders, tested positive for the recreational drug in an out-of-competition test in May last year.
The 28-year-old escaped a sports sanction because the test was not held under the auspices of a sport body.
But his team, Quick Step, were forced to pull him off their Tour de France squad after race organisers expressed concerns.
Boonen was present for Tuesday's procedural audience but told VRT television, "I will only react once a definitive decision has been taken."
According to sources at the prosecutors office Boonen risks between three months and five years in prison and a fine of between 1,000 and 100,000 euros.
Boonen, who recently returned to live in Belgium from Monaco, admitted to cocaine use in June and tried to win back fans' support with a public apology.