"This will mean that from time to time we will enlist the support of experts in their craft to work with our players."
Lehmann said spin bowling would be crucial to eighth-ranked Australia's success in the tournament.
"There's no better person than Shane to help guide the spinners we select in that squad," Lehmann said.
"He was a gifted cricketer and remains passionate about spin bowling and seeing our players be the best that they can be."
Warne, 44, said he was thrilled with his new role. "I'm excited to be working with Australia's spinners in South Africa," he said. "I'm looking forward to helping them with some intense bowling preparation ahead of the World Twenty 20, where we'll specifically work on tactics and mindset."
Muirhead has been named alongside spin-bowling allrounder Glenn Maxwell in Australia's squad for their three-game T20 series against England starting on January 29 in Hobart.
Despite the modest figures of 1-41 off seven overs in three BBL games for Melbourne Stars this summer, selectors have seen enough in the youngster's loop and raw spin to suggest a future at international level.
Muirhead says he has learned a lot already in his five-game BBL career.
"Definitely last year I was trying to get a wicket with every ball," Muirhead said. "But I've had a couple of sessions with Shane Warne and it's all bowling to a plan [now]. It could be a three-over plan, or a three-ball plan.
"Setting the batsman up for the delivery that you want to take the wicket with ... so you really have a plan against each batsman and trying to execute that is my game."
Australia T20 skipper George Bailey said Warne, who has captained teams in the BBL and the Indian Premier League, will boost the side on many levels. "I'm thrilled to have him on board as a spin coach, but he brings so much more to the table," Bailey said. "He'd be one of the leading thinkers on T20 in the world, tactically."
- AAP
