Jose Mourinho apparently accosted referee Fernando Teixeira in the Nou Camp car park after Real Madrid's 2-2 Copa del Rey match with Barcelona on Wednesday.
Teixeira chalked off a Sergio Ramos goal and then dismissed the defender for a debatable challenge on Sergio Busquets.
According to bystanders, Mourinho confronted the referee 90 minutes after the game had ended and launched into a furious rant.
Witnesses claim that the Real Madrid boss screamed: "Hey, some guy you are.
"Why do you just love always f**king up the professionals?"
Wednesday's draw meant that Real Madrid were eliminated from the Copa del Rey.
