Royal Adelaide Show organisers are refusing to remove a Michael Jackson sign at the entrance to a ride called Hard Rock, despite eyebrows being raised on social media, with one user describing it as a "sick joke".

Key points: The controversial rock star's image is being used to indicate minimum height for the Hard Rock ride

The controversial rock star's image is being used to indicate minimum height for the Hard Rock ride There has been a mixed response on social media, with one person describing it as a "sick joke"

There has been a mixed response on social media, with one person describing it as a "sick joke" Show organisers say no offence has been raised directly with them, and that the sign will stay

The cut-out of the controversial pop star is being used as a height restriction indicator on the ride pitched at teenage thrill seekers, and is accompanied by the words "ride the ultimate hard rock".

It follows heated debate about Jackson's legacy in the wake of disturbing allegations of child sex abuse against him in a documentary earlier this year.

A picture of the cut-out has been posted on popular Instagram account ShitAdelaide on the first day of this year's show, attracting reactions ranging from stinging criticism to amusement.

"Must be a sick joke," one said.

Another took aim at the show, saying they "didn't think this through", while another described it as "wrong on many levels".

The show's marketing manager Kirrilee Hay said no complaints had been raised directly with show authorities and, at this stage, the ride's operator would not be asked to remove it.

"We've had no other complaints about it," she said.

"Unless we hear from more people that there is offence there, we wouldn't be taking any action on this.

"The height restrictions are essential to the safety of our rides and our carnival so it's highly important that we have them in that area."

'Enough to make anyone's head spin'

Earlier this year, Michael Jackson tribute artists defiantly committed to continue performing his songs, including at the Adelaide Fringe festival.

The same ride and sign both featured at the Garden of Unearthly Delights during Adelaide's Mad March festival season.

The Hard Rock features "a spinning gondola" swinging to a height of 20 metres. ( Royal Adelaide Show )

According to the Royal Adelaide Show's website, the Hard Rock is a "fan favourite" which features "a spinning gondola" on a pendulum "swinging to a height of 20 metres".

"It's enough to make anyone's head spin," the website states.

The latest controversy follows a decision by safety regulator SafeWork SA to ban some rides from this year's show over safety concerns.

Ms Hay said the first day of the show had been blessed with fine weather.

"The stars have aligned and everyone is enjoying themselves," she said.

"We're expecting around 50,000 through the gates today."