The cause of death of popular Greek singer Giorgos Mazonakis remained undetermined following a forensic examination Friday, with toxicological and other laboratory tests expected to shed further light on the circumstances, authorities said.

Greek musician Giorgos Mazonakis, 54, died in Athens after a reported cardiac arrest. His official cause of death has not yet been announced.

Greek pop star Giorgos Mazonakis, who also enjoyed a strong following among the Greek diaspora, has died of a heart attack after being rushed to a hospital in Athens. He was 54.