Cause of death: pancreatic cancer
Artemios "Demis" Ventouris-Roussos ( ROO-sohss; Greek: Αρτέμιος "Ντέμης" Βεντούρης-Ρούσσος, IPA: [arˈtemi.oz ˈdemiz venˈduriz ˈrusos]; 15 June 1946 – 25 January 2015) was a Greek singer, songwriter and musician. As a band member, he is best remembered for his work in the progressive rock music act Aphrodite's Child, but as a vocal soloist, his repertoire included hit songs like "Goodbye, My Love, Goodbye", "From Souvenirs to Souvenirs" and "Forever and Ever".
Roussos sold over 60 million albums worldwide and became "an unlikely kaftan-wearing sex symbol".
Source : Wikipedia