Cole, 25, from a gunshot, but did not state whether he shot himself or was shot by someone else, The Dallas Morning News reports.
This isn't MMA's first brush with the deadly "game" of Russian Roulette.
He later tweeted that the police are "investigating witness accounts" and "evidence at the scene raises questions".
"They think it's something else other than the Russian Roulette type thing".
"Some say it was about money, someone said something about Russian Roulette, but I don't have any facts now".
"The death of Mr. Cole will be classified as an unexplained death pending the results of the autopsy", the statement read.
Cole was just 25-years old and had just celebrated his two-year-anniversary with his wife, Kymberli Cole, the day before his passing.
In the past four years, Cole had won only two of five professional MMA fights, according to records obtained by The Dallas Morning News. Former UFC heavyweight champion Kevin Randleman passed suddenly in February, rising Bellator MMA prospect Jordan Parsons died following a harrowing hit-and-run incident, boxing great Muhammad Ali left us aged 74 years old, and of course Kimbo Slice died of heart failure in the same week. His license was also suspended for one year.