Tune controversially escaped punishment this summer after admitting using a banned drug to treat a knee injury.

An Australia Rugby Union tribunal found Tune guilty of doping but did not punish him, citing "exceptional circumstances".

The IRB said it was disappointed that the ARU had not taken action against Tune but said the case against the player was now closed.

But the IRB added that it would be looking into why Queensland or ARU officials did not immediately report the violation, which took place last year.

"An enquiry will now be initiated into the background and circumstances of the case," said IRB spokesman Chris Rea.

Tune was picked for the Wallabies' 27-man squad for the four-Test tour of Argentina, Ireland, England and Italy.

Untried trio

Three uncapped players, Queensland flanker David Croft, Australia under-21 fly-half Matt Giteau and New South Wales Waratahs hooker Adam Freier have been included in the squad.

Rising star Giteau, who will also provide cover at scrum-half for skipper George Gregan, said his selection was "completely unexpected".

"I know George Smith is pretty happy too considering he's no longer the youngest player on tour and doesn't have to baby-sit the Wallaby mascot," he said.

The world champions will play one-off Tests against Argentina, Ireland, England and Italy on four consecutive Saturdays starting on 2 November as part of their preparations for next year's World Cup in Australia.

Australia squad

Forwards: Matt Cockbain, David Croft, Ben Darwin, Owen Finegan, Adam Freier, David Giffin, Justin Harrison, Toutai Kefu, David Lyons, Patricio Noriega, Jeremy Paul, George Smith, Nick Stiles, Daniel Vickerman, Bill Young.

Backs: George Gregan (captain), Matthew Burke (vice-captain), Elton Flatley, Matt Giteau, Daniel Herbert, Chris Latham, Stephen Larkham, Stirling Mortlock, Mat Rogers, Wendell Sailor, Ben Tune, Chris Whitaker.