The pre-trial confinement of the basketball player has been extended until July 2.
Mark and Deena Zaru of ABC News reported that a Russian court extended the detaining at the request of the investigators.
In February, Griner was arrested at Sheremetyevo International Airport near Moscow for possession of cannabis, which is not legal in Russia.
The United States government classified her as being "wrongfully imprisoned" last month.
The U.S. government was able to shift its focus away from the legal process and towards trying to bring Griner home as quickly as possible.
Bill Richardson, a former U.S. ambassador to the UN, agreed to work on the case, according to the report.
Despite the U.S. government's change in philosophy and reports of a possible prisoner swap with Russia, Griner remains in custody.
The 31-year-old was a star at the college level and has been in the league for three years. She was in Russia in February to play professional sports.
She is a seven-time All-Star, two-time scoring champion, two-time WNBA Defensive Player of the Year and one-time WNBA champion.
The US national team won two gold medals at the 2016 and 2020 Summer Olympics.
Every team in the league has placed a sticker on their court in support of the player.