A Moscow court has extended the arrest of WNBA star Brittney Griner until May 19, according to the Russian state news agency Tass.

Griner was detained at a Moscow airport on February 17 after Russian authorities said a search of her luggage revealed vape cartridges. They were identified as containing oil derived from cannabis, which could carry a maximum penalty of 10 years in prison.

"The court granted the request of the investigation and extended the period of detention of the U.S. citizen Griner until May 19," the court said, according to Tass.

The United States embassy in Moscow did not immediately return calls from The Associated Press seeking comment.

The 31-year-old Griner, one of the most recognizable players in women's basketball, has won two Olympic gold medals with the U.S., a WNBA championship with the Phoenix Mercury and a national championship at Baylor. She is a seven-time All-Star.

The WNBA season opens May 6.

Griner has played in Russia for the last seven years in the winter, earning over $1 million per season -- more than quadruple her WNBA salary. She last played for her Russian team UMMC Ekaterinburg on Jan. 29 before the league took a two-week break in early February for the FIBA World Cup qualifying tournaments. She was arrested in Moscow upon returning to Russia.

Former Secretary of State Hillary Clinton joined a growing contingent of family, friends and officials calling for the player's release with a "Free Brittney" tweet Wednesday.

It's unclear how much progress was being made in the case because Griner's group has been trying to work quietly for her release and declining to talk publicly since her arrest was made public earlier this month.

"Everyone's getting the strategy of say less and push more privately behind the scenes," WNBA Commissioner Cathy Engelbert said. "It's the strategy you get from the State Department and administration. It's our No. 1 priority in talking with her agent and strategists."

The U.S. State Department has been "doing everything we can to support Brittney Griner to support her family, and to work with them to do everything we can, to see that she is treated appropriately and to seek her release," spokesperson Ned Price said Tuesday at a briefing.

Griner was one of a dozen WNBA players who played in Russia or Ukraine this past season. All except Griner have left since Russia invaded Ukraine.