LaLiga chief Javier Tebas has said Barcelona president Joan Laporta should resign if he is unable to offer a reasonable explanation regarding payments made to a former senior referee.

It was revealed last week that Barca paid over €1.3 million to Jose Maria Enriquez Negreira -- who was the vice president on the referee's committee at the time -- between 2016 and 2018, when Josep Maria Bartomeu was the club's president.

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However, while those are the only payments being investigated by the tax office, it has also been disclosed that Barca paid Negreira over €7m dating back to at least 2003 spanning multiple presidencies. Laporta's first spell in office was between 2003 and 2010.

Barca have not denied the payments and said they were for "technical reports" on refereeing, which they claim is commonplace in football, while Laporta has merely questioned the timing of the leaks.

"If he does not explain what they were paying for, I think he should step down," Tebas said on a call with reporters when asked if Laporta should resign.

"He has not offered a reasonable explanation for these payments. In Barca's statement, it was as if every football club does the same. It is evident they do not. One thing is to have ex-referees [offering advice]; another is to have ex-referees who are on the refereeing committee.

"[Laporta] will have to explain why, in his first spell as president, he did this. It is something I would like cleared up. It's not just the three seasons [being investigated by tax office], it's many more."

Tebas has already confirmed that, regardless of the outcome of the ongoing investigation, Barca will not face any sporting sanctions as over five years has elapsed since they stopped paying Negreira, who refereed in LaLiga between 1977 and 1992. The statute of limitations in a new sports law in Spain is three years.

He said LaLiga will collaborate with the investigation and, if Barca are found guilty of any criminalities, the league will decide what next steps they will take.

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Meanwhile, Sevilla and Espanyol have both released statements questioning the payments made by Barca and demanding a full and transparent response to the reason behind them.

They are the only two top-flight clubs to speak out so far, but Tebas said there is unease across the league.

"There is a lot of concern among the majority of clubs, including Barcelona," he added. "It's doing huge damage to Spanish football. [The clubs] want it investigated until the very end. Barca have also started an internal investigation."

Barca's payments to Negreira stopped in 2018. El Mundo reported last week that he then threatened to reveal "irregularities" if they did not resume them. He never did. A further report in El Mundo on Tuesday also suggested he attempted to blackmail the Royal Spanish Football Federation [RFEF] when he was released in 2018.

In his testimony as part of the case, he told investigators he provided "verbal consultancy" and that he had never benefited Barcelona, nor been responsible for assigning them referees.

"Barca wanted to ensure that refereeing decisions were not taken against them," he said, per the inspector's report. "That is to say, that everything was neutral."