Levante defender Gustavo Cabral was unhappy with the performance of referee Undiano Mallenco in Sunday's 4-2 defeat at Real Madrid.
The Valencia-based club picked up an early lead just five minutes in but found themselves on the back foot in the second half after Vicente Iborra was shown a second yellow card for handball inside the Levante area.
"Here in Spain, a huge importance was given to the fact that Madrid could go 10 points clear of Barcelona," Cabral is quoted as saying by EFE.
"The referee was on Madrid's side. There were many errors which hurt us and yes, we can say that we were robbed.
"Iborra's sending off hurt us, it would have been a different match without that. Madrid piled the pressure on us with one more man on the pitch.
"Perhaps it bothers people that a club as humble as Levante are as high in the league as we are."
Cabral, who scored Levante's opening goal at the Bernabeu, then noted that Sergio Ramos should also have seen red for his deliberate kick on Asier Del Horno during the first half.
"It seems that he [referee] forgave him," he added.
Levante remain in fourth place despite the defeat, but are now just one point ahead of Atletico Madrid, Malaga and Osasuna.