Former Dallas Cowboys defensive lineman Junior Siavii was found dead in a Kansas prison on Thursday as he was awaiting trial ... officials said Friday.
He was 43 years old.
A spokesperson for the U.S. Bureau of Prisons told the Kansas City Starthat Siavii was discovered unresponsive at a federal prison in Leavenworth on Thursday afternoon.
The spokesperson said Siavii was taken to a nearby medical facility where he was pronounced dead.
Further details surrounding the death are unclear ... though The Star did report that the spokesperson said no other staffers or inmates were injured.
Siavii -- real name Saousoalii Siavii -- was being held at the prison after he was hit with multiple criminal charges in 2019.
Federal prosecutors say the former football player was a part of a large conspiracy to distribute methamphetamine. They also allege, among other things, that he illegally had firearms on his person during a wild arrest back in August 2019.