The AFL has sanctioned 13 current and former GWS players in the wake of the Giants' post-season function, with the league describing their behaviour as "completely unacceptable".

Josh Fahey was suspended for four matches, while Jake Riccardi, Joe Fonti, Toby McMullin, Harvey Thomas and the de-listed Cooper Hamilton received two-week bans.

Giants captain Toby Greene was fined $5,000, as were Lachie Whitfield, Connor Idun, Tom Green, Sam Taylor and Lachie Keeffe.

Harry Perryman, who has since joined Collingwood as an unrestricted free agent, was fined the same amount.

The AFL punished the players for breaching its rule relating to "conduct unbecoming" after investigating allegations of inappropriate behaviour at the Giants' end-of-season function on September 18.

The league was tipped off after receiving an anonymous complaint the following day.

The Giants had adopted a theme of "controversial couples" for the function, wearing costumes and performing skits.

In a media statement, the AFL said some of the skits were "completely unacceptable and totally at odds with the code's values".

The AFL said Fahey dressed as a former NRL player — reportedly Jarryd Hayne — and "simulated inappropriate acts on a sex doll".

McMullin and Hamilton "simulated the September 11 terrorist attack on the World Trade Centre", according to the AFL.

Idun and Whitfield enacted a scene from the movie Django Unchained, characterising slavery.

Greene, Taylor, Green, Keefe and Perryman were fined for failing to "display appropriate levels of leadership reasonably expected of each of them in failing to step in to stop the acts continuing".

"The behaviour and the disrespect the players have demonstrated at this event do not uphold any of the values of the AFL or the Giants and the behaviour is not acceptable in any setting at any time," AFL chief executive Andrew Dillon said.

"There is nothing funny or clever about these actions and we are not as a code and competition prepared to accept these behaviours.

"We are also very disappointed that none of the leaders sanctioned sought to stop the behaviour.

"I do want to pay credit to whoever it was who made the anonymous complaint and thank them for refusing to walk past the behaviours.

"These actions do not represent who we are as a code or who the Giants are as a club that has worked hard to build respect across the western Sydney community.

"We have spent a lot of time, resource and energy working with staff, players and clubs to build environments of respect – respect for women, respect for people of different cultures, respect for the wider community – but clearly, we still have work to do.

"And we are committed to doing that work."

Greene apologised for the behaviour of the Giants players.

"As a leader of the club and captain of the team, I am embarrassed that we are in this situation and that I failed to uphold my responsibilities as a leader to prevent it," he said in a Giants statement.

"I am disappointed I did not adequately process the situation, and intervene, in the moment.

"Some of the costumes and skits that took place are unbecoming and contrary to the values of our club and standards we expect of the playing group.

"I understand that as leaders we need to learn from this situation and ensure it never happens again."

Giant chief executive David Matthews said there was no excuse for the players' behaviour.

"As a club built on the values of inclusiveness and respect for all, it was a clear breach of the club's policies and values as well as a significant departure from the standards of behaviour that we expect of our players," he said.

The Giants will provide education sessions for the entire playing group in relation to violence against women, and racial and religious vilification.