In Liberal Senator Michael Ronaldson's words, he was "larger than life in every step of the word".

Mr Marios died yesterday morning. He is believed to have suffered a heart attack at his Nerrina home.

Yesterday, Senator Ronaldson said he had known Mr Marios for about 25 years and described the Ballarat restaurateur and identity as an incredibly generous person.

"He did a lot behind the scenes that very few people would be aware of. He helped people but didn't make a song and dance about it," he said.

"Everyone knew of Nick's politics - he was passionate, but no one was ever offended by it."

Senator Ronaldson spoke with admiration of the work Mr Marios had done in setting up his business, the Sturt Street cafe-delicatessen The Olive Grove and pizzeria Nick's.

He said the cafe was always busy and attracted people from all walks of life.

"The way he and Vicky set it up and ran the business is a great success story in itself," he said.

"From the party's point of view, it will be a great loss; from Ballarat's point of view it will be a loss as well."

Ballarat mayor Judy Verlin, who knew Mr Marios through her associations with the Liberal Party and the community in general, yesterday paid tribute to "a true Ballarat icon".

"Nick could be best described as a loveable larrikin, generous giant and a great big softie at heart," she said.

"He was fiercely loyal to his family and friends. Nick's stories will be sadly missed."