Russian curler Alexander Krushelnitsky, who tested positive for the banned substance meldonium at the Winter Olympics, said Tuesday he had never knowingly doped and welcomed an investigation into the “shock” result.

Krushelnitsky had passed rigorous vetting to attend the Pyeongchang Games, raising questions over the testing programme and the move to let Russians compete despite systemic doping at the 2014 Sochi Olympics.

“I more than anyone else am interested in an investigation as soon as possible to find out the reasons for what has happened,” Krushelnitsky said in a statement published on the website of Russia’s curling federation.

“I am ready to confirm that not once in the whole time that I have been in sport have I taken any banned substance or competed dishonestly in any way,” he said.

The positive test result was “not just a shock – it was a heavy blow to my reputation and my career,” he added.

Krushelnitsky, 25, won the bronze medal in the mixed doubles curling with his wife Anastasia Bryzgalova.

The drug he is said to have taken, meldonium, increases endurance and helps recovery. Russian tennis star Maria Sharapova served a 15-month ban after testing positive for the substance in 2016.

But Russia’s sports minister Pavel Kolobkov said it was impossible that 25-year-old Krushelnitsky could have deliberately taken meldonium.

“In this case, the athlete could not have used the banned drug intentionally, it would be simply pointless. Curling, as a whole, is not the kind of sport in which dishonest athletes use doping,” Kolobkov said in comments carried by news agencies.

“No one is blaming anyone now, but the fact remains. We need to work out how and when the drug got into the body,” he added.

‘A provocation’

Earlier the Russian Olympic Committee (ROC) confirmed the positive result and expressed “deep regret” over the incident.

But it said the concentration of meldonium was “absolutely insignificant from the point of view of any sort of therapeutic effect on the human body,” adding that Krushelnitsky’s previous tests had come back negative.

The ROC said it would begin a comprehensive investigation into the case.

“We completely share and support the IOC and WADA position of zero tolerance for doping and will take all necessary measures to ensure guilty parties are punished to the fullest extent,” the statement added.

Krushelnitsky was one of 168 athletes passed as “clean” and allowed to compete as neutrals after a targeted testing programme stretching back over several months.

Russian curling federation president Dmitry Svishchev earlier dismissed the case against Krushelnitsky as a “provocation, a subversive act”.

Russia were banned as a team from the Olympics in December after investigations revealed an extensive doping plot culminating at the 2014 Winter Olympics that it hosted in Sochi, where Russia topped the medals table.