Rochester Police said the investigation into the cause of death was pending, and that “there is no threat to the public”.
The Glasgow-born singer-songwriter and actor, known as Darius Danesh when he made his first bid for fame on the ITV show Popstars in 2001, also appeared on the first Pop Idol series, which was won by Will Young in 2002.
He went on to forge a successful stage career, appearing as Billy Flynn in two runs of Chicago, as well as in Guys And Dolls, Gone With the Wind and others in the West End including Funny Girl alongside Sheridan Smith.
In 2011, speaking about reprising the role of Flynn, he revealed he had based his portrayal of the character on Cowell.
Campbell Danesh, who starred in the musical opposite America Ferrera, star of the US sitcom Ugly Betty, said: “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 credited Cowell with persuading him to take on the role in Chicago in the first place, saying: “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.”
However, following his appearance on Pop Idol, he turned down Cowell’s offer of a record deal and signed with Steve Lillywhite, with his debut single, Colourblind, going straight to number one in 2002.