The American basketball star who was arrested in Russia on allegations of drug smuggling was detained Feb. 17, a U.S. congressman told ESPN, providing the most detailed public account yet of how long Brittney Griner has been in custody.

And U.S. efforts to get Griner out of Russia are complicated by strained relations between the two countries β€” a deterioration exacerbated by Russia's war with Ukraine, U.S. Rep. Colin Allred told ESPN on Wednesday.

"I do think that it's really unusual that we've not been granted access to her from our embassy and our consular services," Allred, D-Texas, told ESPN.

"The Russian criminal justice system is very different than ours, very opaque. We don't have a lot of insight into where she is in that process right now, but she's been held for three weeks now, and that's extremely concerning," Allred said.

News of Griner's arrest broke in the U.S.Β last weekend, with Russian media reporting she was detained at a Moscow airport on some unspecified day in February. Many details still are in question, including precisely where she is now.

Russian authorities said Griner, 31, had cannabis oil in her luggage while at the airport and accused her of smuggling significant amounts of a narcotic substance, an offense the Russian government says is punishable by up to 10 years in prison.

Basketball star Brittney Griner's arrest in Russia on allegations of drug smuggling has brought widespread condemnation in the US but few details from Russian authorities on her status and the investigation.

Griner, a two-time Olympic basketball gold medalist and WNBA star, plays for the Russian club UMMC Ekaterinburg during the WNBA offseason. A photo posted to social media on February 16 appears to show Griner at a hotel in New York's John F. Kennedy International Airport. Four days later, Griner's Russian team played in a game, and she was not in the lineup.

As word spread in the U.S. of Griner's plight, legislators have pushed for the federal government to intervene. The Biden administration is working to try to get Griner out of Russia, members of the Congressional Black Caucus said after meeting Monday with President Joe Biden.

The backdrop of Russia's invasion of Ukraine, which has led to widespread international condemnation and the severing of many diplomatic ties, has led analysts and government officials to note it may be very difficult to get Griner and other Americans incarcerated in Russia back home.

Supporters of Griner and two Americans who've been detained in Russia much longer, Trevor Reed and Paul Whelan, have been pleading for help freeing their loved ones, even as diplomatic channels fade.

Reed, 30, and Whelan, 52, were arrested and convicted separately for alleged crimes they've emphatically denied well before the Russian incursion of Ukraine, and the pair remain in prison, serving extended sentences denounced by U.S. officials as unfair.

"What's obviously different (in Griner's case) is that Brittney is an extremely high-profile athlete, and it's happening during the course of a Russian-begun war in Ukraine, in which we are deeply opposed to what they're doing," Allred told ESPN.

Allred hopes the U.S. can move quickly to get Griner out of Russia, he told ESPN.

"I'm sure her lawyer in Russia is working through the process, but every day for anyone being held, particularly being held overseas, is a lifetime," Allred said. "I recognize that for her friends and family, this must be incredibly difficult time. And for her, I'm sure the uncertainty about what's happening is probably just terrible. And so, hopefully, whatever happens, we can get this moving quickly and get her out."

Little clarity over what comes next

The scarcity of details provided by Russian authorities has troubled those close to Griner and has others asking what, if anything, can be done to ensure her safety and freedom while Russian troops mount their offensive against Ukrainians.

Citing a law enforcement source, the Russian news agency TASS identified an American woman arrested on drug charges at a Moscow airport as Griner, according to The New York Times. The Russian Federal Customs Service confirmed the arrest of an American athlete in February yet did not identify the person by name nor the exact date of the arrest, per a statement initially reported Saturday by Russia's Interfax News Agency.

The customs service said the American was placed in pretrial detention and noted a criminal case was opened for smuggling significant amounts of narcotic substances, and the offense carries a punishment of up to 10 years imprisonment.

"The customs inspection of the hand luggage being carried by the US citizen confirmed the presence of vapes with specifically smelling liquid, and an expert determined that the liquid was cannabis oil (hash oil), which is a narcotic substance," the customs service said.

Russian state-owned news channel Russia 24 reported a photo was taken by authorities of Griner at a police station holding a sign with her name on it.

Organizations such as the WNBA, the Phoenix Mercury and the WNBA players' union have shared their concerns for Griner and their hopes for her safety. The WNBA's other players have left Russia and Ukraine, it has said.

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CNN's Lucy Kafanov, Paul P. Murphy, Holly Yan, Steve Almasy, Kelly McCleary, Allie Malloy, Wayne Sterling, Elizabeth Joseph, Valery Yegorov and Colin McCullough contributed to this report.