Greek legend and singer Demis Roussos has died aged 68 at the Hygeia Hospital in Athens has confirmed to the BBC.
A veteran selling over 60 million albums, he was best known for his solo hits in the 1970s and 80s, including Forever and Ever, Goodbye and Quand je t'aime.
He became a familiar figure when a member of progressive rock group Aphrodite's Child.
Roussos was best associated with his off-screen role in Mike Leigh's 1977 TV play Abigail's party, having provided the party's soundtrack.
He had been in the private hospital with an undisclosed illness for a period of time
Fellow Greek, Nana Mouskouri paid tribute on French radio RTL: "He had a superb voice, he travelled in the world ... he loved what he was doing.
"He was an artist, a friend. I hope he is in a better world."
The singer was born Artemios Ventouris Roussos in Alexandria, Egypt, in 1946, to a Greek father and Egyptian mother of Italian origin.
He was raised there until his parents moved to Greece in the early 60s after losing their possessions during the Suez Crisis.
Roussos began his music career at 17, when he joined the a band called The Idols, where he met his future Aphrodite's Child bandmate Vangelis.
Aphrodite's Child produced three albums including It's Five O'Clock and The Apocalypse of St John, and enjoyed huge success in Europe in the late 1960s, especially France.
Roussos went on to enjoy a successful solo career, topping the charts in several countries with Forever And Ever in 1973, before doing the same in the UK in 1976.
In 1978 he decided to keep a lower profile and moved to Malibu Beach in the US.