Charles Jillings has resigned as chairman of Harlequins in the wake of the fake blood controversy.
In a lengthy statement on the club's website, Jillings said: "As chairman I am ultimately responsible for all decisions.
"I apologise unreservedly to all our stakeholders for inadvertently compounding the issues. The escalation of these issues in the public domain needs, I believe, a clear response.
"In this context I have decided to resign as chairman and director. Ultimately this happened under my watch, and the failure to control must fall at my door."
Malcolm Wall, who has been conducting an internal review into the so-called Bloodgate episode, has replaced Jillings as interim chairman.
Harlequins' former director of rugby Dean Richards ordered winger Tom Williams to fake a blood injury in the dying minutes of last season's Heineken Cup quarter-final against Leinster.
With Quins trailing 6-5, Williams bit on a fake blood capsule and left the field, allowing previously substituted fly-half Nick Evans to return in an attempt to win the game.
Richards has been banned from rugby for three years, the former Quins physio Steph Brennan was suspended for two years and Williams for four months following an appeal.
Harlequins were fined £260,000 (€295,051), although they escaped expulsion from the Heineken Cup.
Williams and Quins had lied at the initial disciplinary hearing but the player decided to provide a full disclosure of events at the appeal, which reflected particularly badly on the club.
Jillings has tonight sought to clarify his actions and has strongly denied ever attempting to bribe Williams into keeping silent.
Williams was offered a new four-year contract plus other benefits.
Jillings states that while he did initially believe a limited appeal would be the best course of action for Williams to take, he ultimately changed his mind.
"With hindsight my judgement can be called into question by the proximity of my suggestion of limited disclosure by Tom Williams on the one hand, and a financial package proposal on the other," said Jillings.
"My intention was that he was compensated for the damage created by our failure to control (Dean Richards). Under no circumstances was the financial proposal a reward for silence."
Jillings insisted he was not made aware of the cover-up orchestrated by Richards until after the initial hearing, when Williams decided to appeal against his 12-month ban.
"We, Harlequins, acknowledge that we failed to control Dean Richards. I trusted Dean. As a result of the board's failure to exercise control, the club cheated. This is totally unacceptable," said Jillings.
"The board was unaware of these facts until Tom Williams came forward on Wednesday July 29, after the initial ERC hearing.
"I returned from holiday on August 3 to address the findings of the ERC hearing. However, I was faced with the full extent of the devastating revelation that we had cheated and lied in our statements.
"As a consequence Dean Richards had tendered his resignation. I was shocked. The situation was very complicated and raised a number of moral dilemmas for everybody involved.
"I advised the board that Harlequins would accept and publicly acknowledge the judgement and pay the record fine. We would not appeal.
"During those four days, August 3 until August 7, I sought a solution, not a cover-up. I, and the board, had been completely unaware of the cheating during the Heineken Cup quarter-final game and lying subsequently."
Jillings continued: "During this incident I have at all times tried to steer a path that was fair to the individuals concerned whilst acknowledging the club's failings in this matter.
"I am very conscious that these events may not look edifying or for that matter convincing to everybody on the outside."
Wall was Harlequins chairman between 1997 and 2000 and has been conducting the internal review instigated by the board following the initial ERC judgement.
He said: "I am very sorry to take over from Charles in these circumstances. The club has correctly admitted that there were a series of inappropriate behaviours during and following the Leinster game.
"Charles has decided to stand down as these events took place on his watch.
"However, the club owes a great deal to Charles as chairman. He has overseen and led the investment for the development of the club and the stadium as well as the revival in playing fortunes.
"I hope to work with the board and management team to build on his legacy, to put this sorry episode behind us and rebuild the reputation of the club."