(CNN) US basketball star Brittney Griner testified in a Russian courtroom Wednesday as part of her ongoing trial on drug charges, telling the court she had no intention of smuggling drugs into the country.
"I still don't understand to this day how they ended up in my bags," said Griner, who has been detained in Russia since February, when authorities said they found cannabis oil in her luggage at a Moscow airport and accused her of smuggling significant amounts of a narcotic substance. She faces up to 10 years in prison.
Griner -- who plays in Russia during the WNBA's offseason -- pleaded guilty earlier this month, a decision the defense hopes will be taken into account by the court and perhaps lead to a less severe sentence. But the US State Department has classified Griner as wrongfully detained, and her supporters have called for her release, fearing she might be used as a political pawn amid Russia's invasion of Ukraine.
Griner's testimony Wednesday concluded just before CNN reported the Biden administration has offered to exchange a convicted Russian arms trafficker as part of a potential deal to secure Griner's release, as well as Paul Whelan's, another American detained in Russia, according to people briefed on the matter.
These sources told CNN the plan to trade Griner and Whelan for Viktor Bout -- who is serving a 25-year US prison sentence -- received the backing of President Joe Biden after being under discussion since earlier this year. Biden's support for the swap overrides opposition from the Department of Justice, which is generally against prisoner trades.
Griner, who arrived at the Khimki regional court near Moscow on Wednesday in handcuffs, testified that when she was stopped at the Sheremetyevo airport on February 17, she was made to sign different documents without fully understanding what they included.
Initially, Griner said, she signed some documents but was using Google translate on her phone and barely knew what was in them. She was later taken to another room, she said, where her phone was taken away and she was made to sign more documents without an explanation.
No attorney was present, Griner testified, and she said her rights were not explained to her, which, according to Russian law, should have occurred within three hours. Those rights would include her right to know what she was suspected of and to have access to a defense attorney from the moment she was detained -- including the ability to have a private meeting before her first interrogation by authorities.
Griner's detention, search and arrest were "improper," her attorney, Alexander Boykov, told journalists Wednesday, adding he would elaborate during the trial's closing arguments, which are expected in "a couple of weeks."
In her testimony, Griner "explained to the court that she knows and respects Russian laws and never intended to break them," Griner's other lawyer, Maria Blagovolina, said after Wednesday's hearing.
"She emphasized that she never planned to bring it to Russia and use it. She also told the court that Ekaterinburg became her second home, and she has always enjoyed her time in Russia," Blagovolina added, referring to the Russian city where Griner played.
Wednesday's hearing -- the trial's sixth -- was, like earlier ones, attended by US Embassy chargé d'affaires Elizabeth Rood.
The trial is expected to end early next month, Griner's lawyers have said.
The decision to plead guilty was Griner's alone, a source close to her said. For weeks, Griner, her family, lawyers and experts had discussed the decision extensively, and given the 99% reported conviction rate in Russian criminal cases, Griner was urged to weigh all the factors, including a plea which could ultimately result in a shorter sentence.
At the start of her trial, a prosecutor accused Griner of intentionally smuggling drugs into Russia, but Griner later told the court she had not meant to commit a crime, according to state media agency RIA Novosti. The cannabis oil was in her luggage, she said, as a result of her packing in a hurry.
Griner reiterated that statement in her testimony Wednesday, telling the court she was aware of Russia's drug laws and had not meant to break them, adding that she was in a rush and "stress packing."
Griner's attorneys have told Russian judges their client was prescribed medical cannabis for "severe chronic pain." And when asked Wednesday how she received cartridges with cannabis oil in the United States, Griner said she used a medical permit document issued in Arizona to buy marijuana from a pharmacy for medical purposes.
Griner had a bad knee injury, she said, that put her in a wheelchair for four months, and she used medical marijuana when her knee and ankle joint were inflamed. But she never used it prior to tournaments, she testified, because of the risk it would lead to disqualification.
"No, I would never risk that," she said. "I never wanted to hurt my team."
In a hearing Tuesday, Griner's attorneys called a narcologist as an expert witness, who testified "medical cannabis is a popular treatment specifically among athletes" outside of Russia, according to Blagovolina.
Boykov stressed the defense's position is not that Griner was "allowed to import" banned substances into Russia, but they hoped to show the court "even in the United States, where it is allowed, she used these substances occasionally as prescribed by a doctor, strictly for medical purposes to relieve pain."
"We continue to insist that, by indiscretion, in a hurry, she packed her suitcase and did not pay attention to the fact that substances allowed for use in the United States ended up in this suitcase and arrived in the Russian Federation," Boykov said.
Before Wednesday's news that the Biden administration has offered to exchange Griner and Whelan for Bout, there had been speculation she could be released in a prisoner swap, similar to Trevor Reed, an American veteran who was detained in Russia for three years before his release in April.
But before any potential prisoner swap, it was expected Griner would have to be convicted and also admit fault, a senior US official previously told CNN.
Griner's detention has become a focal point for high-profile American athletes, including USWNT soccer star Megan Rapinoe and four-time NBA champion Steph Curry who called on those listening to stay focused on achieving her release at last week's ESPY Awards.
"As we hope for the best, we urge the entire global sports community to continue to stay energized on her behalf," Curry said, when joined by WNBA stars Nneka Ogwumike and Skylar Diggins-Smith to address the issue.
"She's one of us, the team of athletes in this room tonight and all over the world. A team that has nothing to do with politics or global conflict."
Griner's wife, Cherelle Griner, spoke with President Joe Biden and Vice President Kamala Harris earlier this month after publicly criticizing the administration's response to her wife's detention.
Cherelle Griner said she was "grateful" for the call, but added she would "remain concerned and outspoken" until her wife was home.