Sheahan presented new evidence at his appeal on Monday

The Munster player tested positive for the drug Salbutamol after the province's Heineken Cup semi-final against Toulouse in April.

He was then handed a two-year ban by the European Rugby Cup tribunal which would have ruled him out of this year's World Cup.

However, an appeal by Sheahan was heard by a three-man European Rugby Cup panel on Monday where a decision was taken to reduce the ban to three months which has already elapsed.

He has also been fined 5,000 Euro.

The ERC adjudication accepted new evidence presented by Sheahan which argued that the player's dehydration in the heat of Toulouse had given rise to the higher levels of Salbutamol.

"On that basis, while the Appeal Tribunal upheld the finding of a doping offence under the ERC Anti-Doping Programme, it concluded that it would be appropriate to exercise its discretion to reduce the two-year sanction imposed by the Judicial Tribunal," said an ERC statement.

The player and the management of Munster were grossly negligent in the way in which the Player Consent Form was completed ERC statement

The ERC rejected Sheahan's assertion that the failed drugs test had merely been "an administrative oversight".

He claimed he had forgotten to properly inform authorities that he was using a Ventolin inhaler to combat his asthma.

"Both the player and the management of Munster were grossly negligent in the way in which the Player Consent Form was completed and the penalty must be severe to deter such a cavalier approach in the future," added the statement.

The original tribunal found that the player's level of Salbutamol was 20 times higher in the sample collected after the Toulouse game than was the case after the quarter-final tie against Leicester.

Sheahan, who made his Ireland debut three years ago and has won 13 caps, continually protested his innocence.

The Appeal Committee consisted of Jeff Blackett (chairman, England), former England prop Jeff Probyn, and Dr Roger Evans from Wales.

Ireland's 30-man World Cup squad will be announced next Sunday and Sheahan, with the three-month ban having already elapsed, could now edge out Ulster's Paul Shields for the third hooker position.