An "extremely disappointed" West Coast has addressed a recent incident involving a spectator and Fremantle player Michael Walters during last Saturday's Western Derby.

The AFL, Optus Stadium and both clubs are continuing to investigate the matter which took place as Walters left the field, with the Dockers veteran receiving "aggressive and loud" abuse from the spectator in question.

West Coast commented on the incident on Tuesday, condemning the actions of the patron while placing support behind Walters.

"The West Coast Eagles are aware and extremely disappointed regarding an incident after last weekend's RAC Derby where a spectator made crude and offensive remarks to Fremantle forward Michael Walters as he was leaving the field of play," a club statement read.

"The club has reached out to support Michael Walters and are strong in our position that all players should not be exposed to abusive and anti-social behaviour.

"This type of behaviour has no place in our game and players and club staff are entitled to operate in a safe environment and should be treated with due respect.

"The incident is the subject of an investigation by the AFL and the Stadium and the club fully supports that enquiry."

Fremantle football boss Joe Brierty stated on Tuesday that the abuse directed to Walters was not of a racial nature, but was significantly upsetting.

"We're still working through [the investigation] with the stadium and the AFL," Brierty told SEN. 

"It was a really poor act and not what we want to see for our players. They need to see a safe environment when they leave the field. It was really disappointing to see how it occurred.

"It's something we're working through, as a club we're right behind 'Sonny' and supporting him."

No known outcome from the investigation is currently known.