La Liga president Javier Tebas claims 'there would have been no problem" if Manchester United were to sign Neymar this summer.
The Brazil international left Barcelona and completed a world-record transfer to Paris Saint-Germain on 3 August. The Ligue 1 outfit triggered his €222m (£198.6m, $263m) release clause, which allowed the forward move to Parc des Princes.
There were attempts to block Neymar's move to Paris as the La Liga rejected the French club's payment of the €222m release clause. However, the Catalan club later confirmed the player has paid his mammoth buyout clause, which allowed him to join PSG.
French publication L'Equipe claims Neymar was close to joining United last summer as Jose Mourinho's side were ready to trigger his then release clause, which stood at €190m (£170m, $225.7m).
The 25-year-old had then agreed to personal terms with the Red Devils, only to make a U-turn as he changed his mind last summer and continue at Barcelona. Tebas says PSG is a state-backed club and he is hoping to end such situations in the future.
"It is a contractual relationship between Barça and the player. If Neymar goes to the club and deposits €222 million Barça will have no choice but to accept it," Tebas told RAC1.
"What we want to understand is the origin of this €222m, if it is illegal."
"If Manchester United were to come, there would be no problems, we would have nothing to say because it is not a doped club. PSG is a state-run club and we have to end this situation," the La Liga chief added.
It is not the first time that Tebas has publicly criticised PSG. Even before Neymar's deal was confirmed, the La Liga president wanted to take action against foreign clubs who have an illegal advantage over the Spanish clubs.
"We will do it because it violates the Uefa's financial fair play regulation and the competition rules from the European Union," Tebas told Mundo Deportivo.
"We will take the case to Uefa and if they ignore it, we will take it to the Swiss courts and to Brussels, and we do not rule out going to the French and Spanish courts. We are going to present it immediately," Tebas said to Mundo Deportivo.
According to Sky Sports, Neymar signed a five-year deal at PSG will earn around £515,000-a-week ($681,139 per week) after tax. The total value of his transfer including the transfer fee, wages and bonuses could rise up to nearly £450m (€500m).