"I do believe that sledging is a legitimate weapon as long as it does not become abusive. Foul language or an aggressive tone are signs of a frustrated player," Warne said.

"I found it an extremely effective tactic against an insecure batsman who could be intimidated. South Africa's Darryl Cullinan springs to mind as a good player who was not confident against Australia, particularly leg spin. On the other hand, with Sachin Tendulkar and Brian Lara, it was better to be friends and make them smile rather than wind them up," he wrote in his column for The Times.

Warne touched upon the issue in the wake of the racism row involving Harbhajan Singh and Andrew Symonds.

"The sledging issue has become topical again after the Harbhajan Singh appeal - even being described as un-Australian by Michael Jeffery, the Governor-General," Warne said.