Mental As Anything founding member and songwriter Andrew "Greedy" Smith has died after suffering a heart attack in his car. He was aged 63.
The band confirmed Smith's death on its Facebook page "with an incredibly heavy heart".
"Our grief and confusion at this time are little compared to what Andrew's family will be feeling," they added.
According to Australian media, Smith was moving into a new home with his fiancee Fiona Docker when he fell ill.
An ambulance attended the scene, but attempts to revive him failed.
The singer, songwriter and keyboardist was currently on a tour with Mental As Anything, and was the last original member still performing with the band.
Affectionately known as "The Mentals", they were one of Australia's most popular bands in the 1980s, scoring hits with songs like Too Many Times, If You Leave Me, Can I Come Too? and The Nips Are Getting Bigger.
They scored a UK hit in 1987 after their single Live It Up featured in the soundtrack to Crocodile Dundee.
Formed as a party covers band in 1978, Smith always maintained their success had been a fluke.
"We didn't have any ambition at all!" he told NQ Music Press in 2014. "It was someone else's idea to record us, they started an independent record company and they needed someone to record and they picked us, and it was just luck and everyone liking The Nips Are Getting Bigger that started it all off.
"So we said, 'this is easy! We weren't even trying!'"
The band were inducted into the Australian Recording Industry Association Hall of Fame in 2009. Last month, Smith was added to the Australian Songwriters Hall of Fame.
Outside music, the gregarious, articulate frontman was a well-loved TV personality, appearing on Australian shows like Hey Hey It's Saturday and Tonight Live.
He played his last show with Mental As Anything on Saturday night, and had been scheduled to perform in Melbourne on Thursday.
One of the band's founding members, Reg Mombassa, said the group was in shock that their friend had died so suddenly.
"We are all totally shocked. He seemed like such a healthy, energetic guy," he said.
"He wasn't the kind of guy who partied too hard. He enjoyed a drink when we were younger but he was a very serious performer."
Smith is survived by his son Harvey, fiancee Fiona Docker and brother Stuart.