"The most important thing is that he (Muralitharan) does not chuck," Warne was quoted as saying in the Colombo-based Daily News on Saturday.
Warne, Test cricket leading wicket-taker with 566 wickets in 120 Tests, is currently in Sri Lanka to raise funds for tsunami survivors. His closest rival to the world bowling record is Muralitharan, who has 532 Test scalps.
The Sri Lankan, born with a bent elbow, was called thrice for 'chucking' by Australian umpires and then reported last March by English match-referee Chris Broad during the third Test against Australia in Colombo.
In contention was Muralitharan's 'doosra', a delivery that turns away from right-handed batsmen instead of coming into them like a conventional off-break.
"I think it's the way he bowls that has raised a few eyebrows," said Warne.
The Australian also played down his spin rivalry with Muralitharan, saying he had always got along well with the Sri Lankan.
"There has been so much said and written about us going for the world record, rivalry and things like that. I don't think there's so much rivalry. We always get along okay," said Warne.
Warne, who called Muralitharan "soft-hearted" for pulling out of the Australian tour last year, recently said he had promised the Sri Lankan he would do anything possible for the tsunami victims.
The spin greats joined hands for the relief efforts and visited various parts of the country, including the tsunami-devastated Galle stadium where Warne bagged his 500th Test wicket last year.
"It's always good fun to catch up with Murali here in Sri Lanka or in Australia," the paper quoted Warne as saying.
"We always spoke about spin bowling. Spoke about who's hard to bowl to. Murali thinks it's Brian Lara, but I believe Sachin Tendulkar is hard to bowl to."
Warne also lauded the efforts of Muralitharan and his team-mates for raising funds for tsunami survivors.
"Anybody who thinks of Sri Lanka thinks of Murali," he said. "Sri Lanka is Murali, the face and the big black eyes."