Welsh's Prem future on the line
London Welsh's Aviva Premiership fate this season could effectively be decided at a disciplinary hearing next Tuesday.
The top-flight newcomers are currently engaged in a relegation scrap with Sale Sharks and London Irish and have only six games left.
But they will now face a Rugby Football Union competitions hearing after being charged with fielding an ineligible player, scrum-half Tyson Keats, in "a number" of Premiership games this season.
Press Association Sport understands that the issue relates to nine of the 13 Premiership games in which Keats has featured this season.
English rugby's governing body also said that London Welsh's former rugby manager Mike Scott is the subject of a separate RFU disciplinary hearing relating to the registration of the same player.
Scott has been charged under RFU Rule 5.12 for "conduct prejudicial to the interests of the union or the game". Scott's case will be heard at a later date.
London Welsh said tonight that they brought the matter to the RFU's attention after conducting an internal investigation earlier this month.
The club also said they wanted to stress than no fault in the matter resides with Keats.
London Welsh chief executive Tony Copsey said: "This is obviously a serious matter which the club has not only brought to the attention of the RFU, but is also working closely with the RFU to provide full co-operation while the case is being prepared and ultimately heard next week.
"Due to the sensitive nature and the impending hearing, the club is unable to make any further comment at this time."
Welsh are currently three points above bottom club Sale. Should the Keats verdict go against them, they could be facing a considerable points deduction - possibly enough to relegate them - and a probable fine.
In a statement, the RFU said: "London Welsh are to appear at an RFU competitions hearing charged with fielding an ineligible player in a number of Aviva Premiership matches this season.
"The case relating to the registration of scrum-half Tyson Keats will be heard on Tuesday, March 5, by a panel of Jeremy Summers (chairman), Premiership Rugby chief executive Mark McCafferty and Dr Julian Morris at the offices of Slater & Gordon, Chancery Lane, London.
"The club's former rugby manager Mike Scott is the subject of a separate RFU disciplinary hearing relating to the registration of the same player, and has been charged under RFU Rule 5.12 for 'conduct prejudicial to the interests of the union or the game'.
"That case will be heard at a later date."
Welsh's arrival in the Premiership was not confirmed until last summer, and only then after winning their appeal against a RFU ruling that they had not met sufficient criteria to gain Premiership entry, namely primacy of tenure at Oxford's Kassam Stadium where they have played their home games this term.
The appeal panel agreed with the club's argument that the applied criteria contravened EU and UK competition laws, and Newcastle were relegated after finishing bottom of the Premiership last season.
Keats, a 31-year-old New Zealander, joined London Welsh from now-defunct Italian club Aironi.
He started last Saturday's Premiership game against Exeter and has been an important part of their debut top-flight campaign.
Before Christchurch-born Keats headed to Europe, he played Super Rugby for the Crusaders and Wellington-based Hurricanes, and also featured in the colours of Taranaki and Nelson Bays.
London Welsh begin a six-game run-in to their Premiership campaign next Sunday when they tackle Saracens at Allianz Park.
They then face Gloucester and Bath, both away from home, before hosting Northampton, visiting fellow strugglers London Irish and then hosting Worcester on May 4 - the Premiership's final round of regular season action.
The last Premiership club to be docked points were Exeter. They received a two-point deduction and £5,000 fine in April 2011 for fielding too many overseas players in a league game against Leeds Carnegie.