The Olympic Athletics from Russia (OAR) team have announced the opening of a criminal investigation into curler Alexander Krushelnitsky's positive drugs test.
The athlete, who won bronze in the mixed doubles event alongside his wife Anastasia Bryzgalova, tested positive for meldonium on Tuesday.
The OAR announced the investigation after failing to find evidence of the use of the drug, which was banned in 2016.
"No evidence of the systematic usage of meldonium is available in this particular case," a statement from the team read.
"Therefore, the Russian Olympic Committee has initiated a comprehensive investigation of the circumstances, which also includes the criminal investigation under the Russian Federation criminal law to establish the facts of the case in detail."
The OAR sit 20th in the medal table, having won 11 medals in Pyeongchang so far.