British WBO middleweight world champion Billy Joe Saunders has been fined £100,000 by the British Boxing Board of Control for a social media video that police described as "sickening".
Saunders, 29, has apologised for the video, in which he tells a woman he will give her £150 worth of drugs to perform a sex act.
The BBBofC found him guilty of bringing the sport into disrepute and issued a severe reprimand as well as the fine.
The fine will go to a BBBofC charity.
The charity will use it to assist ex-boxers and ex-licence holders who have fallen on hard times.
"You have a responsibility as a boxer, as a high profile sportsman, not to take advantage of people," Saunders' promoter, Frank Warren, told BBC Sport.
"He knows that now better than anybody. It was very poor judgement on his behalf, and hopefully that's behind him now."
In the clip Saunders was also seen asking the woman to punch a passer-by, which she does, before he drives off.
Police have started an investigation into the incident.
No drugs could be seen in the video and the fighter later described it as "banter" that "went wrong".
"Apologise to everybody who's took offence - totally in the wrong, can't do anything but be sorry," Saunders tweeted.
Unbeaten Saunders is due to defend his title against American Demetrius Andrade in Boston on 20 October.