Real Madrid acted inappropriately when allegedly giving referee Jesus Gil Manzano a gift bag after their controversial win over Villarreal on Sunday, according to the latter's president Fernando Roig.
Zinedine Zidane's men ran out 3-2 winners at Estadio de la Ceramica despite finding themselves 2-0 up in the second half and Gil Manzano was the subject of significant criticism for his part in that.
The referee harshly penalised Bruno Soriano for handball in the penalty area and Cristiano Ronaldo converted the resulting spot-kick to equalise after Gareth Bale had pulled one back, with Alvaro Morata then scoring the winner.
Roig then fanned the flames of controversy by claiming Gil Manzano left the stadium with a Madrid gift bag - a common practice among some Spanish football clubs.
And while the president has now apologised to the Royal Spanish Football Federation and the referee's team - who returned to their vehicles to see notes reading "thieves" - Roig once again questioned the appropriateness in presenting a gift bag to Gil Manzano.
Roig's statement read: "Villarreal CF fully relies on the professionalism, integrity and loyalty of the arbitration team and has never doubted or insinuated the contrary for the simple fact that a club has possible gifts for them.
"However, in order to promote total transparency and following the Manual of Regulatory Compliance implemented by LaLiga for all the clubs this season, we do not consider it appropriate to present presents to the referees of a match.
"Villarreal regrets and sincerely apologises to the referee team last Sunday, led by Jesus Gil Manzano, for the message that they found in their vehicles at the exit of the stadium, which deeply rejects.
"Villarreal wishes to express its total and absolute support and respect for the arbitration group in all its levels. We have always valued and defended the honesty and independence of the referees and we will continue to do so.
"Villarreal understands the difficult task of referees and assumes their successes and mistakes as part of the sporting spectacle, as do players and coaches in a football match."