According to reports, the Russian Federal Customs Service at Sheremetyevo International Airport in Moscow stopped the basketball player after they found marijuana in her luggage.
The customs service said that they had won two Olympic gold medals for the United States basketball team, but they didn't reveal the name of the person they were detaining.
The player was held at the airport in February.
A law enforcement source told the Russian news agency that the player was the one who was taken into custody.
According to a statement released by the customs service, it plans to launch an investigation regarding large-scale transportation of drugs, which could carry a sentence of up to 10 years in prison.
The statement was released by the Phoenix Mercury.
We are keeping a close eye on the situation with the player in Russia. We are in constant contact with her family, her representation and the NBA. At this time, our main concern is her safety, physical and mental health, and her safe return home.
USA Basketball also released a statement.
USA Basketball @usabasketballUSA Basketball is aware of and closely monitoring the legal situation facing Brittney Griner in Russia. Brittney has always handled herself with the utmost professionalism during her long tenure with USA Basketball and her safety and wellbeing are our primary concerns.
Tensions between Russia and the United States, as well as several other countries, have arisen due to Russia's invasion of Ukraine.
American officials believe that Russia has been unjustifiably detaining and sentencing Americans on padded charges in recent years, with the profile of Griner potentially making her leverage for a prisoner exchange.
The Mercury's star player since entering the league is 31 years old. She is a seven-time All-Star, two-time scoring champion and one-time WNBA champion.
The Associated Press Player of the Year award and NCAA Final Four Most Outstanding Player award were both won by Griner while he was at Baylor.
In addition to her playing in the NBA, she has also played in Russia. In order to maximize earnings, many players play overseas in addition to their WNBA responsibilities.
The agents for several of the players in the league told the sports network that they planned to leave Russia because of the situation in the country.
The NBA season is set to begin in May, and players typically play in Russia until April before returning to the US.