Egyptian champions Zamalek have quit the current Premier League season, the club has announced on its website.
Zamalek’s board met after a 3-2 loss to El-Gaish on Sunday evening and decided not to complete the competition.
The board are due to meet again on Monday to discuss the matter further.
The Egypt Football Association says it is yet to receive any official communication from Zamalek and has defended the standard of officiating in the league.
The Cairo-based club had unsuccessfully appealed the appointment of referee Mahmoud El-Banaa and believed his designation was to aid rivals Al Ahly.
El-Banaa issued a red card to one of Zamalek’s players after four minutes and awarded two penalties to El-Geish during the match.
“The referee was appointed for the match despite the board’s objection,” the statement continued. “It seems that what happened was on purpose to stop Zamalek’s fine run and also to support our opponents who lost in their last match.”
Under current rules, sixth-placed Zamalek run the risk of relegation to the fourth tier if they don’t reverse their decision.