Villarreal president Fernando Roig is irked that the referees who officiated his team's game against Real Madrid left La Ceramica stadium carrying plastic bags with the logo of La Liga leaders Real.
The visitors came from behind to win 3-2 on Sunday evening and reclaim top spot in La Liga.
"What has surprised me and made me laugh is that the referees have come out [of the stadium] with Real Madrid [plastic] bags," Roig told Cadena Cope radio. "They were carrying [plastic] bags of Real Madrid. I don't know what they had in those bags.
"Our coach did not like that the refereeing delegate came to say goodbye and while he shook our coach's hand, with the other he was holding a Real Madrid bag. He didn't like it. I don't think that is good."
Roig added to Marca: "I just don't think it's a good image. They tell me it's common. But they have not come out with Villarreal bags."
The Spanish Referees' Committee (CTA) told Marca that the bags which the referees were carrying after the game only had Real Madrid merchandising such as "keychains, pins and pens."
Spanish referee Jesus Gil Manzano had been under scrutiny 12 minutes into the second half after awarding Real Madrid a questionable penalty for a handball on Villarreal's Bruno Soriano.
Toni Kroos had taken a shot and after Villarreal's Victor Ruiz stuck out a leg to block the effort, the ball struck Bruno on the arm.
Real trailed 2-0 at the time but equalised thanks to a Cristiano Ronaldo spot-kick.
Substitute Alvaro Morata scored the winner seven minutes from time.
"Clearly it was not a penalty," Roig said. "We are told that a rebound does not warrant a penalty for handball and the referee interpreted it another way.
"They [Real] made a great comeback but thanks to a penalty. Had the penalty not been given, we could have held on."