When Nick Evans was having his integrity questioned and his club was "imploding", the New Zealand fly-half doubted whether Harlequins would ever recover from the Bloodgate scandal.

Four years on, Harlequins have not only recovered but they are back in a Heineken Cup quarter-final, against Munster, and in a better place as a club than they were in 2009.

It was against Leinster at The Stoop that Dean Richards, then Harlequins' director of rugby, instructed wing Tom Williams to bite on a fake blood capsule so he could engineer a late substitution.

Richards wanted to get Evans, who was struggling with knee ligament damage, back onto the field in the hope he could kick the winning points in a ferociously tight quarter-final.

Evans could not and Harlequins lost 6-5 but their ruse was rumbled and the knock-on effects of what became known as Bloodgate reached beyond rugby.

Club doctors and physios found their careers under threat. Richards was banned for three years, Harlequins' name was tarnished and Evans had some explaining to do.

"It was really tough for me. There are two games in my career I've never watched again. That is one of them and the quarter-final of the World Cup in 2007 is the other," Evans said.

"It felt like the club was imploding. People were questioning why I play rugby and my part in it - they were questioning my integrity and I took quite a big offence at that.

"Having been involved in the whole process, I had to go the hearings and I heard the kind of things that were going on and what was going to happen to the club.

"I honestly didn't think we would even get up to where we were before never mind where we are now.

"I remember the first game of the next season and George Robson got sent off in the first minute and I was just thinking 'what the hell is going on here?"'

Evans is not proud of his role in the scandal but he harbours no regrets, hinting at a general acceptance among players that using fake blood was common practice at the time.

"What we have achieved in that time is magnificent. A lot of it is down to the group of players and a lot of it has been down to Conor [O'Shea]," - Nick Evans

That has now changed with the authorities much stricter on how blood and concussion injuries are dealt with.

"It is part of my career and part of the club's history. It is not the greatest part but no regrets. I was just doing my job," Evans said.

"You get told to do something and as a rugby player the guys out there put their bodies on the line. We do it for the love of the club and for our coaches.

"It was a pretty tough time, especially going back home and people asking 'what is happening?'.

"You say 'it's been going on for a while and I'm sure it's happened to a lot of other clubs as well'.

"Other clubs are coming out and saying it has never happened and it was like 'well...'. There was a lot of explaining.

"But once people had been given the reprimands they got it was all about getting the club back on its feet."

Twice in the four years since that day, Evans could have left Harlequins and taken the riches in France or Japan but on each occasion he pledged his future to the club.

The reason for his loyalty was a sense of unfinished business. Evans' decision to re-sign in 2010 was key to the Harlequins rebuilding project.

John Kingston, who had been assistant coach to Richards, steadied the ship for most of the 2009-10 season until Conor O'Shea was recruited to lead the club forward.

"A lot of guys could have jumped ship. It wasn't just me that was getting offers. It was guys like Ugo (Monye) and Danny (Care). There were a lot of offers but we stayed together," Evans said.

And the strides have been remarkable. Harlequins won the 2011 Amlin Challenge Cup and the Aviva Premiership in 2012.

This year they are hunting a unique quadruple, having already secured silverware with the next generation of players in the A League and the LV= Cup.

"What we have achieved in that time is magnificent. A lot of it is down to the group of players and a lot of it has been down to Conor," Evans said.

"We sharpened up a few things, the values and what we were as club. We put that to the forefront of the mind.

"I truthfully didn't expect us to win a trophy that quickly. The Amlin was the big one, winning that first trophy since Bloodgate was a big thing for us.

"That was just the catalyst for the Premiership win. Hopefully, we can now take that next step.

"To win (the Heineken Cup) would be the ultimate achievement."