Harlequins have been hit by a misconduct complaint following an incident during their Heineken Cup quarter-final defeat against Leinster last month.

Roger O'Connor, European Rugby Cup's disciplinary officer, launched an initial investigation into circumstances surrounding the second-half blood substitution of Quins replacement Tom Williams and fly-half Nick Evans' resulting return to the playing field.

New Zealander Evans had limped off in the 47th minute, before his replacement Chris Malone was then helped off hurt. Evans, though, reappeared after Williams departed late in the game, with television footage appearing to show Williams winking as he left.

The Guinness Premiership club now face a disciplinary hearing that could result in them being fined or even suffering a points deduction.

O'Connor's probe included gathering statements from match officials, the two teams involved and a review of broadcast footage from the game.

He has now made his decision that the matter should go further, and will present the case against Quins. A disciplinary committee will be convened on a date yet to be announced.

Quins, through their second-placed Premiership finish, have already qualified for next season's Heineken Cup as one of seven English representatives.