Barcelona president Joan Laporta insisted the club have never bought referees after a Spanish court opened an investigation into payments made to the former vice president of the refereeing committee.

In a two-hour news conference on Monday, Laporta said there was a smear campaign against Barca, strongly criticised LaLiga president Javier Tebas and called out Real Madrid's "cynicism" for joining the legal case against the Catalan club.

- Stream on ESPN+: LaLiga, Bundesliga, more (U.S.)

Barca paid ex-referee Jose Maria Enriquez Negreira's company over €7 million between 2001 and 2018.

Prosecutors allege the club sought to gain favour through the payments, but Laporta said they were paying for services related to scouting and technical reports about refereeing.

"Barcelona have never acted with the intention of altering or influencing competitions to gain a sporting advantage," Laporta said.

"The courts have found no proof otherwise because there is none. It is not possible. This is the result of a smear campaign against Barcelona.

"It is the fiercest attack ever against Barcelona and has been done to ruin the club's reputation and destabilise us."

Laporta added that Barca are the victims of a "public lynching" and have not been afforded the presumption of innocence.

"We are taking legal action and have already filed 20 lawsuits against journalists and people for defamation," he said. "We believe we could be due an astronomical amount in compensation for damages."

Since news of the payments broke in February, Laporta and Tebas have become embroiled in a back-and-forth.

The LaLiga chief called the scandal "the biggest reputational crisis" the league has faced, while Barca demanded his resignation following allegations he supplied false evidence to the investigation, which he denies.

"We are witnessing a public trial in which certain people are trying to harm those of us who have not bowed to their demands and wills -- this is intolerable," Laporta continued.

"I would like to single out, in particular, Tebas, who has acted irresponsibly and unprofessionally. With his constant statements, he has fuelled the controversy and even provided false documentation to prosecutors.

"I would ask him to curb his verbal incontinence because it does no favours to the institution he represents.

"The timing is no coincidence, just as Barca are coming out of financial crisis, having rejected LaLiga's CVC agreement and being part of the European Super League."

Laporta also launched an attack on Madrid, Barca's partners in the Super League project, after they decided to add their name to the prosecutor's case last month.

"Real Madrid is a club that has been historically favoured by refereeing decisions; a club that has been considered as the team of the regime [in Spain]," Laporta said.

"It is worth remembering that, for seven decades, most of the presidents of the refereeing committee have been ex-members, ex-players or ex-directors of Real Madrid.

"For 70 years, the people who were there to dispense justice on the field of play have been people connected to Real Madrid. For them to claim they feel wronged is an unprecedented exercise in cynicism."

To justify the payments made to Negreira, Laporta had with him on the stage 629 reports and 43 CDs which he said was the work done between 2014 and 2018 -- previous reports have since been destroyed.

Negreira's links with Barca spanned four presidents, with prosecutors seeking charges against two of them, Josep Maria Bartomeu and Sandro Rosell.

Laporta defended the costs of the services, saying it should be put into context that the €7m was paid over a 17-year period and for work carried out by reputable people in their field. "The main provider of the services was Negreira's son, which is important," Laporta said. "When we arrived [for our first mandate] in 2003, we saw that this was interesting technical work being done by reputable people.

"We didn't see any ethical conflicts, we were using the son of the vice president who had worked with various clubs -- Valencia and Girona I think -- the Spanish federation, with Luis Aragones... it wasn't ridiculous to hire his services."

Laporta said he had increased the payments because the company had taken on more scouting work across more competitions and that the rise was always "in line with market prices."

A Spanish court continues its investigation into the prosecutor's allegations, while UEFA have also opened their own enquiry.

LaLiga cannot sanction Barca because any possible punishment is time-barred, but UEFA could act if the club are found guilty of any wrongdoing.