Gerard Butler is remembering his friend Darius Campbell Danesh days after the singer’s death.
Campbell Danesh, who rose to fame as a contestant on the British music competition series pop idol two decades ago and went on to star in multiple productions on London’s West End, he was found dead in his Rochester, Minnesota, apartment on Aug. 11, according to a statement from his family given to Deadline. He was 41.
On Thursday, the Greenland actor, 52, shared a throwback Instagram photo of him and Campbell Danesh smiling together and paid tribute to the late singer in an emotional caption.
“I am devastated by the sudden passing of my dear friend Darius, a true brother in arms,” he wrote.
Butler offered “thoughts and love” to Campbell Danesh’s “wonderful” parents Avril and Booth, as well as his “two brilliant brothers” Aria and Cyrus.
“To those lucky enough to have met Darius for more than a few minutes, they were deeply moved by his infectious laugh and barely containable zest for life,” Butler wrote.
He praised his friend’s consistent smile, “booming voice” and “genuinely warm embrace that few could resist—nor would they want to.”
Added Butler: “He was an incredible talent, a singer whose voice touched your soul and an actor with great presence. But, most importantly, he had the heart of a lion. It was bigger and brighter than the sun and an energy so contagious.” he could light up a room in seconds.”
He went on to salute the “Colourblind” singer for motivating those around him to strive for their best and said that he remained humble with his “hilarious self-deprecating sense of humor.”
The actor later confessed he’s still trying to digest the reality of Campbell Danesh’s death.
RELATED VIDEO: Olivia Newton-John Was an ‘Angel on Earth,’ Remember Friends: ‘There Will Never Be Another Like Her’
“Somewhere in there I believe there is, or will be, some meaning in why he left us so early. If it was nothing more than teaching us to live with that open heart, putting others first and never taking ourselves too seriously as we learn to traverse this wonky world we live in then, that might be enough,” he said.
While Butler wrote that his “heart aches heavily,” he added that he’s determined to help Campbell Danesh’s legacy stay alive.
“Going forward, I will beat my drum louder and celebrate life and its every beautiful moment because my brother showed me that it was a pretty awesome way to go about it,” he wrote.
Never miss a story — sign up for PEOPLE’s free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from juicy celebrity news to compelling human interest stories.
In his family’s statement about his death, they said local authorities determined “there were no signs of intent or suspicious circumstances.”
His cause of death was not immediately known.