Damian Irvine has quit his post as chairman of embattled Cronulla amid the anti-doping investigation centred on the NRL club.
He has been replaced as chairman by board member Glenn Coleman.
Irvine had been at the centre of controversy since he told a Sunday newspaper Sharks players had been injected with "equine substances".
His comments, made en route home to Australia from an overseas trip, put him at odds with both the rest of the club's board and the playing group.
Board deputy chairman Keith Ward had cited serious management failures when they stood down coach Shane Flanagan and sacked four football club staff, including long-serving doctor David Givney, football manager Darren Mooney and head trainer Mark Noakes.
Ward said the sackings were not related to any alleged doping practices at the club in the period during the 2011 season that is under investigation.
Irvine claimed in Sunday's interview those stood down or sacked had knowledge of illegal practices for some time but did not inform the board.
Announcing his resignation on Wednesday, Irvine said he should not have made those comments.
"I don't think it did (help). And I'm honest it's been a period of time of extreme pressure and strain for a lot of people," Irvine said.
"That conversation I had I won't back away from it. But it wasn't an interview in a calm situation. It was a middle of the night conversation after quite a bit of badgering. It wasn't sensible to make those comments and I'll take responsibility for those.
"I feel my presence at the club may prove be to an obstacle in allowing those affected by the decisions made by the board last week to move forward.
"As a result I'm standing down as chairman of the board of directors today.
"The club needs some time to investigate and plan the way forward without added distraction.
"There's been ill-informed speculation recently reporting the motivation and reasoning of the board's strong action last Friday.
I want to make something perfectly clear.
"Self interest was the furthest thing from the minds of the directors when they took the tough decisions they took last week.
"I believe we made the right decision for the right reasons."
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