Brittney Griner was back in a Russian court on Tuesday for her trial for cannabis possession amid US diplomatic efforts to secure her release.

If convicted, the WNBA star and two-time Olympic gold medallist could face 10 years in prison.

During the hearing, prosecutors called a state narcotics expert who analysed cannabis found in Griner’s luggage.

Her defence team fielded a specialist who challenged the analysis, charging that it was flawed and did not conform to official rules.

Griner was escorted into court in handcuffs and placed inside a cage in the trial in Khimki, a town on the northern edge of Moscow. While in the cage she held up personal photos.

The trial adjourned until Thursday, when closing statements are scheduled.

As her trial has progressed, the Biden administration has faced growing public pressure to get her released.

Secretary of State Antony Blinken spoke to his Russian counterpart Sergei Lavrov last week, urging him to accept a deal under which Griner and Paul Whelan, an American imprisoned in Russia on an espionage conviction, would go free.

The Lavrov-Blinken call marked the highest-level known contact between Washington and Moscow since Russia sent troops into Ukraine more than five months ago.

People familiar with the proposal say it envisions trading Griner and Whelan for the notorious arms trader Viktor Bout.

White House Press Secretary Karine Jean-Pierre told reporters on Monday that Russia has made a “bad faith” response to the US government’s offer, a counter-offer that American officials do not regard as serious. She declined to elaborate.

Griner has acknowledged there were vape canisters containing cannabis oil in her luggage when she was arrested at a Moscow airport in February.

But she insisted that she had no criminal intent and that the canisters ended up in her luggage because she was packing hastily.

Griner played for a Russian women’s basketball team in the WNBA off-season.

Her defence lawyers presented testimony from doctors that she was prescribed cannabis as a treatment for pain. Medical marijuana treatment is not legal in Russia.

While judges have leeway to consider mitigating factors under Russian law, acquittals are rare and account for less than 1% of cases in Russian criminal prosecutions.

A conviction, however, could potentially pave the way for Ms Griner’s exchange as Russian officials said it could only happen after the judicial process is completed.

Tom Firestone, a Washington lawyer who formerly served as legal adviser at the US Embassy in Moscow, said Griner could be handed a tough sentence as a way for Russians “to maximise their leverage in negotiations”.

He said Russia “may want to let this play out a little bit longer and try to extract more concessions”.

Russian officials have dismissed US statements about the case, saying they show a disrespect for Russian law. They urged Washington to discuss the issue through “quiet diplomacy without releases of speculative information”.