The OAR confirmed on Tuesday that Krushelnitsky's second sample has been tested positive for the banned substance on the Russian Olympic Committee's official website, on behalf of the Olympic Athletes from Russia (OAR) delegation in Pyeongchang.
On Monday, the Anti-doping Division of the Court of Arbitration for Sport (CAS ADD) initiated a procedure involving Krushelnitsky, who is suspected of violating the doping rules.
"We express our sincere regret over this incident," the statement says.
However, the delegation has failed to clarify why the athlete used the meldonium, adding that they have launched an investigation into the issue.
"It is well known that the effect of meldonium is achieved by its regular usage, and metabolites are fixed in the human body about nine months after the end of the drug's intake. The concentration of meldonium found in the sample indicates a single use of the drug, which is not used in medical practice, is absolutely meaningless from the point of view of achieving any therapeutic effect on the human body.
"The test taken from Alexander Krushelnitsky before the start of the Olympic Games, on January 22 - as well as all the previous ones - was negative. Thus, the fact of conscious or systematic use of a prohibited substance is not confirmed.
The information is yet to be confirmed by the International Olympic Committee (IOC) or the Court of Arbitration for Sport (CAS).
Krushelnitsky's A sample tested positive on Sunday.
If the positive result of the doping test is confirmed, Krushelnitsky and his wife Anastasia Bryzgalova might be stripped of the bronze they won in the mixed doubles last week (Russia's first ever Olympic medal in curling).
Alexander Krushelnitsky and his wife Anastasia Bryzgalova married last summer. Working together both in life and in sports, they took home several gold medals from the 2016 World Championships and became internet icons of the ongoing 2018 Olympics due to their outstanding good-looks.