Edinburgh have suspended flanker John Hardie until mid-January 2018 after the conclusion of an internal investigation carried out by the PRO14 club.
A statement from Scottish Rugby confirmed that the 29-year-old has received disciplinary action for "gross misconduct".
It read: "As part of a range of sanctions, a three-month suspension from playing for the club has been imposed, running from the date of his initial suspension in mid-October this year.
"He will not be available for selection by Edinburgh Rugby until mid-January 2018, at the earliest.
"John has co-operated with the disciplinary process throughout," an Edinburgh Rugby spokesperson added.
"He has acknowledged the serious mistake he has made as a professional athlete and has accepted full responsibility for his conduct.
"It has been made clear that we are not prepared to tolerate the behaviour which caused this situation.
"Support will be provided to the player by Edinburgh Rugby and Scottish Rugby on a personal and professional level throughout the period of his suspension and going forward."
Hardie was initially suspended by both club and country in October when the investigation was first launched.
New Zealand-born back-rower said: "I would like to apologise to everyone for putting myself in this situation.
"Through my actions I feel I have let my club, my teammates and the fans down," he continued. "I want to acknowledge the support I have had from Edinburgh Rugby and Scottish Rugby in dealing with the issue.
"I am now focused on putting myself in the best possible position to be considered for selection again."