Brittney Griner claims the cannabis found in her luggage was for medicinal purposes ©Getty Images

The United States' double Olympic champion Brittney Griner, who is currently detained in Russia on drug charges, presented a doctor's letter in court prescribing that she can use cannabis to treat pain.

The basketball player was arrested at Moscow’s Sheremetyevo Airport in February after customs officials said they found vape canisters containing cannabis oil in her luggage.

As a result, she faces up to 10 years in prison if found guilty.

"The attending physician gave Brittney recommendations for the use of medical cannabis," said lawyer Maria Blagovolina.

"The permission was issued on behalf of the Arizona Department of Health."

The defence also submitted tests she underwent as part of an anti-doping check which did not detect any prohibited substances in her system.

The next hearing for Griner's case is set to take place on July 26.

Brittney Griner faces up to 10 years in prison on drug smuggling charges if found guilty in Russia ©Getty Images
Brittney Griner faces up to 10 years in prison on drug smuggling charges if found guilty in Russia ©Getty Images

"In the hearings yesterday and today what became very clear is the tremendous amount of respect and admiration both in the United States and here in Russia where Miss Griner has been playing basketball for seven years, not only for her professional achievements but for her character and integrity," said US Embassy charge d’affaires Elizabeth Rood.

The director, Maxim Ryabkov, and team captain, Yevgenia Belyakova, of UMMC Ekaterinburg, for which Griner plays in the offseason, testified on her behalf while US President Joe Biden said he is doing all he can to have her released.

Russian media have speculated that Griner could be swapped for Russian arms trader Viktor Bout, nicknamed "the Merchant of Death," who is serving a 25-year sentence in the US after being convicted of conspiracy to kill American citizens and providing aid to a terrorist organisation.

However, the difference in seriousness of their cases is likely to make such a trade unacceptable for the US.