Ryan, the former England, Newcastle and Wasps number eight, will appear before a Rugby Football Union disciplinary panel in Bristol on March 1.

He must answer what the RFU term "charges of conduct prejudicial to the interests of the Union and the game, contrary to rule 5.12".

The charges relate to post-match scenes at Vicarage Road last Sunday when Gloucester suffered an injury-time 24-22 defeat against Saracens.

Ryan, whose team are major contenders for the Premiership title play-offs, could face a lengthy touchline ban and substantial fine if found guilty.

Ryan felt Leicestershire official Debney, one of the RFU's full-time referees, incorrectly awarded Saracens a late line-out and missed a knock-on from the home side which led to Kris Chesney crashing over for a try.

Chesney's try tied the scores, before Saracens fly-half landed a touchline conversion with the game's final kick to leave Gloucester reeling and an animated Ryan fuming as he remonstrated with Debney as they left the pitch.

In his post-match press conference, Ryan said: "We've lost two games in the final seconds this season because of very poor decisions. I cannot hide my frustrations.

"I cannot rationalise something that can't be explained. Saracens knocked on, we kicked the ball straight into touch and the referee marches us back for a lineout to them just outside our own 22.

"The referee said he called 'advantage over' but I don't believe it. It is another to add to the mysteries of refereeing.

"I know I am not meant to discuss this, and I will probably get into trouble, but I am not going to talk about the other 80 minutes when only one decision mattered.

"I've got 22 people in the dressing room who cannot believe they have lost. This is one of the most pivotal games of our season, and it has been decided by a referee's decision."

Ryan's hearing will be chaired by Christopher Quinlan, and is scheduled two days before Gloucester's Premiership clash against relegation-threatened Northampton.

Ryan, while in charge of Bristol, received a month-long coaching ban in October, 2001 - the suspension only applied on match days - and he was fined £2,000 ($3,850) for criticising referee Tim Miller following a match between Bristol and London Irish.