St George Illawarra coach Paul McGregor has been heavily fined by the NRL club after being charged with drink-driving.
The Dragons confirmed McGregor blew over the limit at a Wollongong roadside test at 8.47am on Sunday, recording a reading of 0.06.
He was charged with low-range drink-driving.
A court date is to be determined.
The Dragons would not disclose the full amount of McGregor's penalty but said in a statement the coach had been "heavily fined".
"Paul had spent his day off with friends and family at a charity event, had a full night's sleep, was up working, had breakfast and then jumped in his car to drive, not thinking that he would be 'over the limit'," Dragons chief executive Peter Doust said.
"Paul understands the seriousness of the matter, regrets his error of judgment, is extremely remorseful and has accepted the sanctions determined by the club."
Doust said McGregor immediately told club management about the incident on Sunday.
However, the NRL confirmed the club first told its integrity unit about the matter when the DUI news broke on Thursday.
McGregor said he was in "total disbelief" when he blew over the limit.
"I'm extremely disappointed with myself and totally understand the problems that can and could have arisen from my poor decision," he said.
"It was a mistake, a gross error of judgment and one that I deeply regret."