Former UK Pop Idol contestant and theatre star Darius Campbell Danesh has been found dead in his US flat at the age of 41, his family have announced.
The singer and actor was found in Rochester, Minnesota, on August 11, although the cause of death remains unknown.
"It is with great sadness that we announce the passing of Darius Campbell Danesh," the family said.
"Darius was found unresponsive in bed in his apartment room in Rochester, Minnesota, on August 11, and was pronounced dead in the afternoon by the local medical examiners' office.
"The local police department have confirmed that there were no signs of intent or suspicious circumstances.
"The cause of his sudden death is unknown at this stage while medical examinations continue.
"We ask that you kindly respect our wishes for privacy at this time whilst we come to terms with the tragic loss of our son and brother."
Simon Cowell remembered Campbell Danesh as “charismatic, funny and just a great person to be with”.
“I first saw Darius on television over 20 years ago and I got to know him really well," Pop Idol judge Cowell, 62, told PA.
“His passing, for someone so young, is an absolute tragedy and my heart goes out to his family and friends.”
Gareth Gates, 38, who found fame after finishing as a runner-up on the first series of Pop Idol, paid tribute in a touching Instagram post.
“I can’t quite believe the news of my dear friend Darius passing," Gates wrote, alongside a picture of himself and Campbell Danesh. "I’m heartbroken.
“Darius took me under his wing during our time in Pop Idol, like a big brother; always looking out for me and for that I thank you my friend.
“I will miss our chats. He was one of the most beautiful, intelligent and gentle souls I was lucky enough to know, a soul that lit up every room.
“Good bye my friend. Forever in my heart. x.”
The Scottish singer-songwriter and actor — who was known as Darius Danesh when he made his first bid for fame in ITV show Popstars in 2001 — also appeared on the first Pop Idol, which was won by Will Young.
After reaching number one in the UK pop charts in 2002 with his debut single Colourblind, Campbell Danesh went on to forge a successful stage career.
He appeared in Chicago as Billy Flynn in two runs of the production, as well as Guys and Dolls, Gone with the Wind, and more in the West End.
Campbell Danesh lived in the US and found love with Canadian actress Natasha Henstridge, whose films include sci-fi hit Species.
The couple married in 2011 at the San Ysidro Ranch in Santa Barbara, California, but were divorced a few years later.
In 2010, he spoke to Hello! magazine about a car crash in which he broke his neck.
The singer had been a passenger in a Porsche when it hit a wall at 100 kph after skidding on oil during a break in Spain.
After coming third in Pop Idol in 2010, Campbell Danesh went on to win the first series of ITV's Popstar To Operastar contest, beating Bernie Nolan of the Nolan Sisters in a close final.
A few months after his win on the ITV show, which featured Welsh singer Katherine Jenkins and Mexican-born tenor Rolando Villazon as judges, he landed his first major opera role after being cast in a production of Carmen at London's O2 Arena.
Campbell Danesh took on the principal role of toreador Escamillo in the production, for a one-off performance that marked the first opera at the venue.
In 2011, speaking about reprising the role of Chicago's scheming lawyer Flynn, he said he had based his portrayal of the character on his old mentor and Pop Idol judge, Simon Cowell.
Campbell Danesh starred opposite Ugly Betty star America Ferrera in the musical set in prohibition-era Chicago.
"He's the consummate businessman and a wonderful guy, and there's a lot of Simon Cowell in Billy Flynn in terms of the way he approaches things and I recognise that in terms of the character," he said at the time.
Campbell Danesh credited Cowell with persuading him to take on the role in Chicago in the first place.
"I'm incredibly grateful for the experiences I've had and all the opportunities that it opened up and to be able to call Simon Cowell a friend and to be able to have dinner with him," he said.