Bystanders sang Shannon Noll's hit song What About Me as the singer was knocked to the ground outside an Adelaide strip club, a witness says.

Alastair Longmuir was outside the club, where his friend worked, when he saw the commotion about 2.30am and recognised the former Australian Idol star.

At some stage the alleged assault occurred and Mr Longmuir said it was at that point Shannon was swiftly taken to the ground by guards.

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What about him? Bystanders sang Shannon Noll's hit song What About Me as the singer was knocked to the ground outside an Adelaide strip club, a witness says

Hindley Street revelers who saw the incident started singing his best-known hit.

'As he was thrown to the ground these strangers started singing What About Me to him,' Mr Longmuir said.

Shannon was arrested in the early hours of Sunday morning outside the Crazy Horse Revue on Hindley Street in Adelaide's CBD.

The 41-year-old was reportedly removed from the club by security guards and later charged with two counts of assault.

'He was yelling and screaming and being really aggressive,' the 19-year-old witness told AAP. 'He was saying, 'I'm Shannon Noll. Let me back into the Crazy Horse'.'

Trouble: Alastair Longmuir was outside the club, where his friend worked, when he saw the commotion about 2.30am and recognized the former Australian Idol star.

Sing a long: 'As he was thrown to the ground these strangers started singing What About Me to him,' Mr Longmuir said

But Shannon's promoter Duane McDonald told The Daily Telegraph, 'He's not the type of person who would say 'Don't you know who I am?', that's not in his character at all'.

He added: 'He's a decent, hardworking family man. I think there's more to this story than what's been seen.'

On Saturday, Noll had performed at the Sounds By The River concert along with John Farnham and Daryl Braithwaite in Mannum, east of Adelaide.

His manager David Woodward said there would be no comment in relation to the singer's arrest or the incident in Adelaide for legal reasons.

Who's that boy? 'He was yelling and screaming and being really aggressive,' the 19-year-old witness told AAP. 'He was saying, 'I'm Shannon Noll. Let me back into the Crazy Horse''

Out of character: Shannon, shown here on a night out with singer Vance Joy last year, is down tro earth says his promoter Duane McDonald. He told The Daily Telegraph , 'He's not the type of person who would say 'Don't you know who I am?', that's not in his character at all'

But he said upcoming tour dates would go ahead, including his scheduled appearance at the Mornington Racecourse on January 21 and 22 as part of the Red Hot Summer Tour.

Other shows he is still scheduled for include the Tamworth Country Music Festival and more Red Hot Summer dates around the country.

'All of Shannon's tour dates are going ahead as planned. He is looking forward to all upcoming show dates,' Woodward told AAP on Monday.

Injured: Shannon broke his shin bone at a concert last year. His manager David Woodward said upcoming tour dates would go ahead

The Australian Idol runner-up has been enjoying a career resurgence of late, more than a decade on from his appearance on the TV talent show.

The incident has not done much to dent his popularity judging by the reaction on social media, with a Facebook post of him performing at Mannum attracting hundreds of supportive comments.

He is scheduled to appear in the Adelaide Magistrates Court on February 24, the day before performing at a concert on Queensland's Bribie Island.