OAR spokesman Konstantin Vybornov issued a statement on Tuesday saying that the "B" sample, which had been opened for testing yesterday, had returned the same result as the "A" sample: a positive for the presence of meldonium.
Norway, which finished fourth, is expected to be given the bronze medal.
The announcement came hours after CAS cancelled the hearing into the case at the request of the International Olympic Committee, the World Curling Federation and Krushelnitsky himself.
Unlike other Russian officials who have suggested Krushelnitsky's food or drinks could have been spiked, Kolobkov warned on Wednesday against hastily jumping to conclusions.
"Unfortunately we have to part with the Olympic bronze medal", he said in a statement on the federation's website.
The IOC forced Russian athletes to compete as neutrals on an OAR team as punishment for the "systematic manipulation" of the anti-doping system at Sochi 2014.
The Court of Arbitration for Sport said no date has yet been set for the curler's hearing.
In a statement, the Russian delegation in Pyeongchang said: "We express our honest regret over the fact of the incident".
The positive test result was "not just a shock - it was a heavy blow to my reputation and my career", he added.
The development has cast doubt over Russia's potential reinstatement by the International Olympic Committee (IOC) before Sunday's (February 25) Closing Ceremony.
His case has been controversial as he was one of 168 athletes who passed rigorous testing to compete as a neutral in Pyeongchang, where Russian Federation are banned following the discovery of systemic doping.
A total of three athletes have tested positive for performance-enhancing drugs in Pyeongchang: Kreshelnitckii, Japanese speed skater Kei Saito and Slovenian hockey player Ziga Jeglic. They also asked South Korea and Japan, where Russian curlers trained before going to the Olympics, to provide data from CCTV cameras.
The IOC emphasized, however, that the Russian delegation could be allowed to fly the national tricolor at the Games' closing ceremony, if the criteria demanded by the IOC are met.