Neath/Swansea Ospreys have cited Munster prop Marcus Horan for alleged racial abuse following Sunday's Heineken European Cup tie at the Gnoll, a match the Irish province won 20-18.

The Welsh club allege the loosehead prop used racist language towards Ospreys centre Elvis Seveali'i, and are believed to have claimed in their formal submission to the ERC that Horan called the Samoan "a black c***".

It is one of three complaints the Ospreys have filed against the 21-times capped Irish prop. They also claim Horan punched Seveali'i and that the Irishman lashed out with his boot at wing Richard Mustoe, catching him with his studs in the face leaving the winger stunned and dazed.

The Ospreys decision to cite Horan came on foot of Munster's undertaking to report Mustoe to the ERC for stamping on Horan's face, an injury that required seven stitches. A Munster official made a courtesy call to the Ospreys to inform the club they would be citing Mustoe on Tuesday to be told if that was the case then the Welsh club would be doing likewise with Horan.

Teams have until 50 hours after the kick-off of the match in question to report a player to ERC. The tournament's governing body unveiled a disciplinary procedure this year and this format meant both teams' complaints have been forwarded to a citing officer. He has reviewed the aforementioned incidents and is expected to confirm later today both players will be called to account the charges against them, most probably next week. ERC released a statement confirming the complaints from the respective clubs.

It read: "ERC, the Heineken Cup tournament organisers, have received citing complaints arising from the Pool 4 match between Neath-Swansea Ospreys and Munster played at The Gnoll on Sunday, October 31st. Citing complaints have been received against Neath-Swansea Ospreys wing Richard Mustoe from Munster and against Munster prop Marcus Horan from Neath-Swansea Ospreys."

If as expected the respective cases proceed, chairman of disciplinary panel Prof Lorne Crear will put together a panel to hear the allegations. Another ERC officer Roger O'Connor would present the case against the players.

The allegation of racial abuse is believed to have come from Seveali'i, who claims Horan launched a verbal tirade at him after the centre high-tackled John Kelly, a transgression for which the Ospreys player was sin binned. The Samoan also claims Horan punched him during this incident.

The Munster Branch released a statement last night staunchly rejecting the allegations made against their player. It read: "Munster accept that Neath Swansea Ospreys are entitled to ask the citing officer to look at any incident that might have taken place in the course of any match under the jurisdiction of ERC Ltd.

"Munster totally refute the very serious allegation of racial abuse made by Neath Swansea Ospreys and further believe that Marcus Horan has no case to answer in relation to the charges levelled against him.

"Munster are also disappointed that Neath-Swansea Ospreys chose to lodge their complaint only after Munster had informed them (Neath-Swansea Ospreys) that they intended asking the citing officer to look at the incident involving Richard Mustoe which resulted in Marcus Horan requiring seven stitches in a forehead wound."

The Mustoe-Horan contretemps arose when the Ospreys wing tackled Horan without the ball - he would subsequently be yellow carded for this transgression by referee Joel Jutge - and as Horan fell to the ground he kicked out with his feet but didn't appear to catch his assailant. The Ospreys allege the Irish international caught Mustoe in the face.

Mustoe got to his feet and as he jumped over a prone Horan propelled his foot backwards, studs first, and appeared to catch Horan in the face. ERC is expected to confirm the Citing Officer's findings at lunch-time today.

Meanwhile, the Munster side to play Ulster in the Celtic League in Ravenhill on Saturday shows 11 changes from the team that started against the Ospreys. Christian Cullen, Shaun Payne, Donncha O'Callaghan (he has been given permission to play by the Irish management because he lacks match practice) and David Wallace alone remain in the side with Payne switching to the right wing to accommodate James Storey at outside centre.

Wallace moves to number eight in a back row that includes Alan Quinlan and Denis Leamy.

Ulster coach Mary McCall has made several alterations to the side hammered by Gloucester last weekend.

Kevin Maggs and David Humphreys are with the Ireland squad and Paddy Wallace is out injured. Johnny Bell returns to the centre, Adam Larkin plays at outhalf, Nigel Brady is out with an eye injured while Roger Wilson damaged an ankle training with the Irish squad. Paul Shields returns at hooker with Campbell Feather coming in at number eight.

ULSTER: B Cunningham; T Bowe; J Bell; P Steinmetz; T Howe; A Larkin; N Doak; S Best; P Shields; R Moore; R Frost; M McCullough; A Ward (capt); C Feather, N Best. Replacements: R Best; R McCormack; G Longwell; G Brown; K Campbell; S Mallon; A Maxwell.

Munster: C Cullen; S Payne; J Storey, J Holland, M Lawler; P Burke, M Prendergast; F Roche, J Flannery, G McIlwham; D O'Callaghan, T Hogan; A Quinlan, D Wallace, D Leamy. Replacements: J Blaney, E McGovern, T Bowman, S Keogh, E Reddan, M Mullins, J Kelly.