Stefan Denifl, who was banned for four years by the UCI after being linked to a blood doping scheme discovered by the Operation Aderlass police investigation, has admitted to doping over a five-year period.

Denifl is facing criminal charges of commercial fraud in the state court in Innsbruck, Austria.

The 32-year-old Austrian raced for the now-defunct IAM Cycling squad and Aqua Blue Sport during the period when he doped (2014-2018), confirming he utilised the services of Mark Schmidt – a former team doctor for Gerolsteiner and – who is alleged to be behind the blood doping ring uncovered by Operation Aderlass.

Denifl's blood bags were reportedly among those seized when authorities raided a garage in Erfurt, Germany early in 2019.

"I am not a criminal," Denifl said in his hearing, according to Tirol.orf.at, saying he started doping after a serious knee injury in order to get his former performance level back and claimed that teams knew that many riders were doping.

"I wouldn't have gotten a contract without doping," he claimed.

Denifl had signed for the CCC Team for 2019 before withdrawing from his contract in December 2018 before the season began. Team manager Jim Ochowicz said there were no warning signs in Denifl's biological passport.

Denifl said he withdrew from his CCC Team contract to spend more time with his family.

"I no longer wanted to [race], I wanted to be with my son, I finally wanted to have a life", he said.

Operation Aderlass unfolded in February 2019, with seven cyclists banned for involvement to date: Denifl, Georg Preidler, Kristijan Durasek, Alessandro Petacchi, mountain biker Christina Kollmann-Forstner, Borut Bozič and Kristijan Koren.

According to the report by the APA agency, representatives from teams who gave Denifl contracts are to be heard as witnesses at the request of Denifl's lawyer.

Although Team Sunweb have vowed to take action against Georg Preidler if it is shown he doped during his time with that team, Denifl's attorney argued that the alleged victims of Denifl's doping – IAM Cycling and Aqua Blue Sport – have not filed any complaints.

Prosecutors say Denifl used a pre-paid mobile phone to communicate with Schmidt since 2016 and banked blood with the nickname 'No name'. They argue that Denifl defrauded sponsors by using performance-enhancing including drugs such as growth hormones, estimating the damages at €580,000. He could face up to 10 years in prison if found guilty.

His lawyer argued that Denifl has already been stripped of his results back to 2014 and has been banned for four years and criminal charges would amount to punishing him twice for the same act.