Dean Richards admits he is devastated that his role in the blood cheating scandal has done so much damage to the reputation of rugby union and his former club Harlequins.

In a statement on Wednesday Richards confirmed he ordered Tom Williams to fake a blood injury in the dying minutes of Harlequins' European Cup quarter-final against Leinster last season.

Richards was banned for three years by a European Rugby Cup disciplinary panel, while Harlequins were fined STG260,000 ($A520,520) and Williams had a 12-month suspension reduced to four months at Monday's appeal hearing.

"I have always been passionate about rugby and in the dying minutes of that quarter-final - a stage Harlequins had never reached before - I allowed my passion for the club to compromise my judgment," Richards said.

"I ordered a blood substitution to be made using fake blood. Thankfully the substitution did not affect the outcome of the game.

"Some eight days later I was told by Tom Williams that, in the heat of the moment and at his direction, he had his lip cut to make it appear as if there had been a real injury if anyone asked to look at it.

"Believing this to be true, I felt a managerial duty and sense of loyalty to safeguard the professional position of those involved.

"From then on, with the agreement of Tom Williams, I suggested the fabrication of a story which led to us all withholding the true facts, a position that was obviously wrong.

"I have since made clear that I accept full responsibility for what happened and have apologised for my actions. I honestly believed that I was acting in the best interests of the club and my colleagues, a clearly mistaken belief.

"I am mortified that this matter has brought damaging publicity on Harlequins, members of its staff, my own family and the wider game of rugby - a game I am passionate about."

Brought to you by AAP © 2024 AAP