Heavy metal singer Warrel Dane from the bands Nevermore and Sanctuary has died today (13 December) from a heart attack while in São Paulo, Brazil.

The American musician was aged 56 and had a heart attack during the night and could not be revived.

Johnny Moraes, who was a member of Dane's solo band, was with the singer at midnight when Warrel began to feel unwell.

He told Brazil's UOL: "He died in the night. He was in the apartment where he stayed during the recording of the album when it happened. I gave him cardiac massage and we called the Mobile Emergency Care Service (SAMU), who came very fast, but when they arrived, he was already dead."

While his Wikipedia page states he was 56, many wrongly believed Dane was 48. He has suffered a history of addictions and health issues, with Moraes adding: "His health was already very weak because of his diabetes and his problems with alcoholism. He was already facing a lot of health problems."

Sanctuary guitarist Lenny Rutledge has also reacted to the news of Dane's passing, posting a Facebook message reading: "Today I wake up to the news that Warrel Dane has died.

"I don't even know what to say. My friend, brother and musical companion for over 30 years has passed away. I'm in total shock right now.

"I'm sorry for any close family or friends that had to hear the news on Facebook."

Fans of the singer are already flooding Twitter with their condolences, with one person tweeting: "Just read that Warrel Dane has passed away. Absolute shock. His work on Nevermore's "This Godless Endeavor" is one of my all-time favorite vocal performances in metal. Was a huge influence on me becoming a metal fan as a teenager."

Another said: "So, Warrel Dane died... Another favourite vocalist of mine gone. F**K. Condolences to his close friends and family."

A third added: "Gonna miss your savage poetry. Have a great ride and thanks for your guidance. May your words be heard, forever."