Former Lidl-Trek and Jumbo-Visma rider Antwan Tolhoek has returned an “adverse” anti-doping test for steroids, the UCI has said.
The 29-year-old Dutchman, who began this season with Portuguese Continental team Sabgal/Anicolor, provided the sample during an out-of-competition control in November 2023, when he was under contract with Lidl-Trek.
Tolhoek has been provisionally suspended from racing, and his contract has been terminated by his team.
In a statement shared on Wednesday afternoon, the UCI wrote: “The Union Cycliste Internationale (UCI) informs that Dutch rider Antwan Tolhoek has been notified of an Adverse Analytical Finding for Anabolic Androgenic Steroids (AAS)1 in a sample collected during an out-of-competition control on 27 November 2023.”
Anabolic steroids are the first substance listed on the World Anti-Doping Agency’s (WADA) Prohibited List, and are outlawed both in and out of competition. They are performance-enhancing drugs that are often associated with muscle-building, allowing riders to train harder and for longer.
Their use can cause severe bodily damage, and lead to heart attacks, strokes and kidney failure.
Examples of anabolic steroids used by athletes include testosterone and nandrolone. The UCI, however, did not cite which substance was found to be present in Tolhoek’s sample.
The Dutch rider now has the right to request the analysis of a second, B sample taken during the same control by the International Testing Agency (ITA), the independent entity that oversees anti-doping in elite cycling.
If the B sample confirms the A sample, or if Tolhoek choses not to request it, he could face disciplinary proceedings.
In a statement shared with Cycling Weekly, Tolhoek's team, Sabgal/Anicolor, said his contract has been terminated with immediate effect.
"Clube Desportivo Fullracing has taken the decision to immediately terminate the Dutch athlete's contract and cancel all of his duties within the club from this moment on," the team said.
"It was only today that Clube Desportivo Fullracing was informed of the result of this adverse control, which relates to the 2023 season. The athlete's registration was made without the club being aware of the situation."
Cycling Weekly has contacted Lidl-Trek, the team the Dutchman rode for at the time of the test. The UCI has said it will not comment further while the investigation is open.
In 2017, Tolhoek received a two-month suspension from his then squad LottoNL-Jumbo after he took sleeping medication on a training camp, outside of the team’s supervision.
News of his adverse anti-doping result comes in the same week that Decathlon AG2R La Mondiale rider Franck Bonnamour was provisionally suspended for “unexplained abnormalities” in his biological passport.
Tolhoek, stage winner at the Tour de Suisse in 2019, was scheduled to compete in the one-day Figueira Champions Classic in Portugal on Saturday.