A small minority of Western Sydney supporters looks to have cost the club a seven-figure sum and potentially a marquee player spot, with the Wanderers' major sponsor set to walk away at the end of the season due to the behaviour of their fans.

NRMA Insurance, which has been the naming rights partner of the Wanderers since the club's inception, will sever ties with the club, pulling the plug on a sponsorship deal worth over $1 million per year.

Naming rights ... and wrongs: NRMA are set to end their sponsorship of the Wanderers, harming the club's ability to recruit marquee players like Oriol Riera. Credit:AAP

NRMA's current sponsorship deal expires at the end of the season, but the insurer has notified the Wanderers that it will not be extending the deal. Fairfax Media understands the company did not want to be associated with the behaviour of the club's active supporter group, the Red and Black Bloc.

There have been regular incidents of illegal, anti-social or offensive behaviour by a small, yet prominent and influential element of the supporter group since it was formed in 2012.