Shane Warne has declared more heads must roll in the wake of Australia's embarrassing defeat in the fourth Test.

Warne unleashed on Cricket Australia (CA) in a post-match tirade following a 492-run loss to South Africa in Johannesburg, having commentated at both the third and fourth Tests.

Shane Warne says change has to continue after Australia's Test series loss. Credit:Vince Caligiuri

"It's a line in the sand for Australian cricket and it's time to say 'right, this is unacceptable, we cannot play like we've seen these last two weeks'," the legendary legspinner said.

Warne also made his thoughts clear on social media.