The singer-songwriter was next week expected to take to the main stage at Port Fairy, and has cancelled all his future shows ahead of a court appearance next month.

Victoria Police confirmed to The Standard that detectives from the Fawkner Sexual Offence And Child Abuse Investigation teams had charged a 36-year-old man following an alleged sexual assault that occurred in Coburg in September 2008.

"A man from Connells Point, New South Wales, has been charged with one count of indecent assault. He was summonsed to appear at Melbourne Magistrates' Court on March 16, 2020," a Victoria Police spokesman said in a statement.

Port Fairy Folk Festival director Caroline Moore advised she was working on adjusting the festival schedule.

"The festival has advised that, due to current circumstances Dan Sultan has cancelled all current performance commitments. He will allow the legal process to take its course before making any further comment," she said.

Sultan had previously cancelled shows following what he described as "inexcusable and disrespectful" behaviour at a show in Cairns in 2018, with some fans having reportedly walked out on his performance.

One spoke on social media of the musician rambling, singing off-key, and falling off his stool, and urged him to get help.

Sultan had spoken of issues with alcohol in the past.

The news comes shortly after Sultan won the ARIA Award for Best Children's Album.

Following the ARIA win, Sultan said his achievement wouldn't have been possible without getting his alcoholism under control.

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