Finn Russell will miss Scotland's RBS 6 Nations clash with Italy after his appeal against a two-week ban was thrown out by tournament bosses.

A Six Nations appeal committee rejected Scotland's appeal against Russell's ban for tackling Dan Biggar in the air in the 26-23 defeat to Wales on February 15.

The appeal committee upheld the original decision to suspend Russell for two weeks, despite considering submissions from the 22-year-old fly-half at a London hearing on Wednesday.

Russell will now miss Saturday's Murrayfield clash with Italy, but will be free to return to face England at Twickenham on March 14.

"The Appeal Committee, having considered submissions on behalf of the player and on behalf of the Six Nations disciplinary officer, dismissed the appeal with the result that the original sanction of a two-week suspension stands, with Finn Russell able to return to play on March 2, 2015," read a Six Nations statement.

Russell had his initial three-week ban cut to two weeks in the first hearing on his case, with disciplinary bosses reflecting on his clean record.

The Glasgow playmaker avoided a lengthy ban as Six Nations chiefs ruled his challenge "reckless rather than deliberate".

Russell collided with Biggar as his Wales counterpart leapt for a high ball into the Scotland half during the first period of Scotland's slender Murrayfield defeat. Ospreys playmaker Biggar landed in a heap, but avoided serious injury and was able to continue.

New Zealand referee Glen Jackson sin-binned Russell, but a Six Nations disciplinary committee ruled the offence warranted a red card following the first hearing in London.

The Scottish Rugby Union (SRU) quickly announced plans to appeal the decision, clearly adamant Russell had collided with Biggar unwittingly and accidentally.

Meanwhile, Glasgow lock Leone Nakarawa has been handed a three-match ban for headbutting Ospreys prop Marc Thomas.

The Fiji international will miss the Guinness PRO12 leaders' games against fellow play-off hopefuls Munster and Leinster as well as a clash with bottom club Zebre.

Nakarawa escaped a red card for the incident, which happened during a scrum in Glasgow's 19-16 weekend win over the Welsh side, but was punished by a PRO12 disciplinary committee.

The committee decided the offence was at the low end of World Rugby's sanctions and removed a week from the minimum four-week ban because of the player's disciplinary record.

The 27-year-old is suspended until March 29, but the punishment took account of two rest weeks for the RBS 6 Nations.