The Brandon Correctional Centre remains locked down as police investigate the death of an inmate.
Jean Paul (J.P.) Beaumont, 39, was found dead on Sunday morning, shortly after 10 a.m. CT.
Court documents show police believe Beaumont, a full patch member of the Rock Machine, was the biker gang's highly placed sergeant-at-arms.
The Rock Machine has been embroiled in a turf war in Manitoba with the Hells Angels and its puppet clubs.
Beaumont's house was shot at in 2010, and he fled the province because he was on bail at the time.
However, he was arrested in Toronto and sent back to Manitoba.
Police in Brandon have not released any details about how he died.