(CNN) Bodybuilder Cedric McMillan has died at the age of 44, his sponsor confirmed Tuesday.
"We regret to inform you that our friend and brother @cedricmcmillan passed away today. Cedric will be greatly missed as an athlete, comrade, friend, and father," Black Skull USA, a supplements company, wrote in a post on Instagram. The company didn't provide further details around McMillan's death.
"Our prayers are with all his family and friends. He 'fought the good fight' and now he rests," it added.
McMillan won the 2017 Arnold Classic bodybuilding competition, and the organizer, the Arnold Sports Festival, said it was "heartbroken" in a tribute on Instagram.
"Known for his larger than life personality, his infectious smile, a gentle heart, and a sense of humor that was loved by fellow competitors and fans alike, Cedric will be deeply missed," the post reads.
The organization is named after famed bodybuilder Arnold Schwarzenegger, and the post includes a photo of McMillan and Schwarzenegger together.
McMillan won multiple titles and became a "star in the world of bodybuilding and fitness," as well as serving for more than 20 years in the US Army, where he rose to the rank of Sergeant First Class, the post continues.
"Above all, Cedric McMillan was a husband and a father, and we send our most heartfelt condolences to his family during this incredibly difficult time," it reads.
McMillan was a member of the South Carolina National Guard at the time of his death, a spokeswoman told CNN. She confirmed that the National Guard had been notified of his death, but declined to comment further.