Krushelnitsky, who won bronze in Pyeongchang with his wife Bryzgalova in mixed doubles curling, tested positive for meldonium, a drug that can aid endurance.
The Court of Arbitration for Sport said on Wednesday it would hear a case against Krushelnitsky on Thursday.
TASS quoted Krushelnitsky saying he "formally broke the anti-doping rules" and a spokeswoman for the curling federation said the admission made it certain they would return the medals won.
"The court would have made the decision to strip us of our medals anyway. But since we really admit the fact that his doping probe was positive for meldonium, we hand back the medals," TASS quoted Valentina Parinova as saying.
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(Reporting by Maxim Rodionov; Editing by Toby Davis)
