FC Barcelona could again face exclusion from the Champions League after Spain's Civil Guard concluded in a report requested by the court how referees under the command of ex-president of the Technical Referees Committee (CTA) Victoriano Sanchez Arminio and his vice Jose Maria Enriquez Negreira weren't always impartial, according to El Mundo.

Earlier this year, the term 'Caso Negreira' entered the lexicon of Spanish football when it emerged that Barca had paid Negreira some €7.3 million ($7.9 million) from 2001 to 2018.

President Joan Laporta denied wrongdoing and insisted that the payments were made for honest consultation work, but still the Catalans were charged with "continued corruption between individuals in the sports field" in March by the Barcelona provincial prosecutor’s office.

This led to UEFA EFA opening its own investigation, with a ban from the Champions League for the 2023/2024 season possible.

In late July, the European governing body revealed that Barca were "provisionally admitted to take part" in its elite club competition, but stressed that a "future decision on admission/exclusion" was still possible.

UEFA indicated that it could reopen its investigation if more evidence emerges, and it will now be alert to El Mundo's report less than 48 hours after Barca were drawn into Group H with Porto, Shakhtar Donetsk and Royal Antwerp in Monaco on Thursday evening.

According to the newspaper, the Civil Guard has concluded that Sanchez Arminio and Negreira ran an "irregular operation" at the CTA, whose decisions "would not have always had an impartial sporting support".

The report added that Barca have still not provided the identity of the professionals who provided services at Negreira's companies invoiced in the payments, and that "copies of videos, documents or reports in which the specific advisory work is carried out" have also not been delivered.

As of yet, neither Barca nor UEFA have responded to El Mundo's report published on the eve of the Catalans' trip to Osasuna on Sunday.

This is their last fixture ahead of the international break, after which Barca will play their first Champions League match at the Montjuic Stadium on September 19 when they host Antwerp following a September 16 meeting with Real Betis in La Liga.