The White House has secured the release of American basketball star Brittney Griner, according to a U.S. official. The release was in exchange for Russian arms trafficker Viktor Bout, nicknamed the “Merchant of Death,” according to a source familiar with the deal.

The swap, which marks a major diplomatic achievement for President Joe Biden, brings an end to an ordeal that began when Griner was arrested in Russia on Feb. 17 for possession of vape cartridges containing hash oil.

Griner had recently been moved to a Russian penal colony nearly 300 miles from Moscow to serve her nine year sentence.