Belgian cyclo-cross racer Toon Aerts (Baloise Trek Lions) has asserted his innocence after his team confirmed that a banned substance was detected in Aerts' out-of-competition doping control sample taken on January 19.

The sample was taken 10 days before Aerts competed in the UCI Cyclocross World Championships in Arkansas, where he finished in sixth place. If confirmed by the B sample, Aerts would be stripped of his X2O Badkamers Trophy Series title as a result of his victory in Lille on February 6, third place at the Gerbl Superprestige, and a top-10 finish at the Brussels University Cyclocross.

"I will do everything in my power to prove my innocence and clear my name," Aerts said in a statement after being informed that the breast cancer drug Letrozole was found in his A sample, according to Sporza. [Yesterday, my world was turned upside down. I received a letter from the UCI that no athlete wants to receive, informing me that an abnormal result was found in a urine sample taken during an out-of-competition test at my home on January 19."

"How this happened remains unknown to me at this time. A product called 'letrozole metabolite' was detected in my urine sample. I have never heard of this product until yesterday and do not know how it got into my system."

Letrozole is an aromatase inhibitor, used primarily to block estrogen and slow the progression of breast cancer, but also abused by those who use anabolic steroids and want to block their feminizing effects or increase testosterone production by preventing its breakdown. They are consistently banned on WADA's list of banned substances.

Aerts requested further analysis of the B sample, but opted to end the season "until more clarity is obtained."

"Anyone who knows me a little knows that I have been against doping in any form throughout my career and have always done everything I could to set an example as an athlete. [Therefore, I will do everything in my power to prove my innocence and clear my name, and I will refrain from commenting until the B sample is analyzed and further investigated," Aerts concluded. 'I respect this and urge everyone to first give me and my family the time and opportunity to be more clear.'

The Baloise Trek Lions also chose to place Aerts on the inactive list, pending confirmation of the outcome.

"We have given warm feelings to the toon for years and look forward to more good news with him soon. As a precautionary measure and after consultation with Toon, we have decided that he will no longer take action and will be suspended until further details are known," the team wrote.

"At Baloise Trek Lions, doping is strictly prohibited for all players. As a team, we owe it to ourselves, to the other athletes on the team, and to cycling fans."